Move from groowt to own repository.

.gitattributes

@@ -0,0 +1,12 @@
+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew        text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat           text eol=crlf
+
+# Binary files should be left untouched
+*.jar           binary
+

.gitignore

@@ -0,0 +1,8 @@
+# Ignore Gradle project-specific cache directory
+.gradle
+
+# Ignore Gradle build output directory
+build
+
+# Custom
+.idea

build.gradle

@@ -1,10 +1,73 @@
 plugins {
-    id 'GroowtConventions'
     id 'java-library'
+    id 'maven-publish'
+}
+
+group = 'com.jessebrault.di'
+version = '0.1.0'
+
+repositories {
+    mavenCentral()
 }
 
 dependencies {
     api libs.jakarta.inject
+    api libs.groovy
     compileOnlyApi libs.jetbrains.anotations
-    implementation libs.slf4j.api, libs.groovy
+    implementation libs.slf4j.api
+
+    testImplementation libs.junit.jupiter.api
+    testRuntimeOnly libs.log4j.core, libs.log4j.slf4jBinding
+}
+
+test {
+    testLogging.showStandardStreams = true
+}
+
+testing {
+    suites {
+        test {
+            useJUnitJupiter()
+        }
+    }
+}
+
+java {
+    withSourcesJar()
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(21)
+    }
+}
+
+jar {
+    archiveBaseName = 'di'
+}
+
+sourcesJar {
+    archiveBaseName = 'di'
+}
+
+publishing {
+    repositories {
+        maven {
+            name = "Gitea"
+            url = uri("https://git.jessebrault.com/api/packages/jessebrault/maven")
+
+            credentials(HttpHeaderCredentials) {
+                name = "Authorization"
+                value = "token ${System.getenv("GITEA_ACCESS_TOKEN")}"
+            }
+
+            authentication {
+                header(HttpHeaderAuthentication)
+            }
+        }
+    }
+
+    publications {
+        create('di', MavenPublication) {
+            artifactId = 'di'
+            from components.java
+        }
+    }
 }

gradle.properties

@@ -0,0 +1,7 @@
+# This file was generated by the Gradle 'init' task.
+# https://docs.gradle.org/current/userguide/build_environment.html#sec:gradle_configuration_properties
+
+org.gradle.configuration-cache=true
+org.gradle.parallel=true
+org.gradle.caching=true
+

gradle/libs.versions.toml

@@ -0,0 +1,19 @@
+# This file was generated by the Gradle 'init' task.
+# https://docs.gradle.org/current/userguide/platforms.html#sub::toml-dependencies-format
+
+[versions]
+groovy = '4.0.27'
+jakarta-inject = '2.0.1'
+jetbrains-annotations = '26.0.2'
+junit = '5.13.0'
+log4j = '2.24.3'
+slf4j = '2.0.17'
+
+[libraries]
+groovy = { module = 'org.apache.groovy:groovy', version.ref = 'groovy' }
+jakarta-inject = { module = 'jakarta.inject:jakarta.inject-api', version.ref = 'jakarta-inject' }
+jetbrains-anotations = { module = 'org.jetbrains:annotations', version.ref = 'jetbrains-annotations' }
+slf4j-api = { module = 'org.slf4j:slf4j-api', version.ref = 'slf4j' }
+junit-jupiter-api = { module = 'org.junit.jupiter:junit-jupiter-api', version.ref = 'junit' }
+log4j-core = { module = 'org.apache.logging.log4j:log4j-core', version.ref = 'log4j' }
+log4j-slf4jBinding = { module = 'org.apache.logging.log4j:log4j-slf4j2-impl', version.ref = 'log4j' }

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,251 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,94 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'di'

src/main/java/groowt/util/di/AbstractInjectingObjectFactory.java

@@ -5,6 +5,8 @@ import org.jetbrains.annotations.Nullable;
 
 import java.lang.reflect.*;
 import java.util.*;
+import java.util.function.Consumer;
+import java.util.stream.Collectors;
 
 import static groowt.util.di.ObjectFactoryUtil.toTypes;
 
@@ -19,6 +21,89 @@ public abstract class AbstractInjectingObjectFactory implements ObjectFactory {
             Class<?>[] paramTypes
     ) {}
 
+    protected record Resolved(Class<?> type, Object object) {}
+
+    private static final class DeferredSetters {
+
+        private final Class<?> forType;
+        private final List<Consumer<Object>> actions = new ArrayList<>();
+
+        public DeferredSetters(Class<?> forType) {
+            this.forType = forType;
+        }
+
+        public Class<?> getForType() {
+            return this.forType;
+        }
+
+        public List<Consumer<Object>> getActions() {
+            return this.actions;
+        }
+
+    }
+
+    protected static class CreateContext {
+
+        private final Deque<Class<?>> constructionStack = new LinkedList<>();
+        private final Deque<DeferredSetters> deferredSettersStack = new LinkedList<>();
+        private final List<Resolved> allResolved = new ArrayList<>();
+
+        public CreateContext(Class<?> targetType) {
+            this.pushConstruction(targetType);
+        }
+
+        public void checkForCircularDependency(Class<?> typeToConstruct) {
+            if (constructionStack.contains(typeToConstruct)) {
+                throw new IllegalStateException(
+                        "Detected a circular constructor dependency for " + typeToConstruct.getName()
+                                + " . Please use setter methods instead. Current construction stack: "
+                                + constructionStack.stream()
+                                        .map(Class::getName)
+                                        .collect(Collectors.joining(", "))
+                );
+            }
+        }
+
+        public void pushConstruction(Class<?> type) {
+            this.constructionStack.push(type);
+            this.deferredSettersStack.push(new DeferredSetters(type));
+        }
+
+        public void popConstruction() {
+            this.constructionStack.pop();
+            this.deferredSettersStack.pop();
+        }
+
+        public boolean containsConstruction(Class<?> type) {
+            return this.constructionStack.contains(type);
+        }
+
+        public void addDeferredSetterAction(Class<?> forType, Consumer<Object> action) {
+            boolean found = false;
+            for (final DeferredSetters deferredSetters : this.deferredSettersStack) {
+                if (deferredSetters.getForType().equals(forType)) {
+                    found = true;
+                    deferredSetters.getActions().add(action);
+                    break;
+                }
+            }
+            if (!found) {
+                throw new IllegalArgumentException(
+                        "There is no construction for type " + forType.getName() + " which should be deferred."
+                );
+            }
+        }
+
+        public List<Consumer<Object>> getDeferredSetterActions() {
+            return this.deferredSettersStack.getFirst().getActions();
+        }
+
+        public List<Resolved> getAllResolved() {
+            return this.allResolved;
+        }
+
+    }
+
     private final Map<Class<?>, Constructor<?>[]> cachedAllConstructors = new HashMap<>();
     private final Collection<CachedInjectConstructor<?>> cachedInjectConstructors = new ArrayList<>();
     private final Collection<CachedNonInjectConstructor<?>> cachedNonInjectConstructors = new ArrayList<>();
@@ -81,14 +166,27 @@ public abstract class AbstractInjectingObjectFactory implements ObjectFactory {
         return null;
     }
 
+    private static boolean areArgsAssignable(Class<?>[] paramTypes, Object[] givenArgs) {
+        if (paramTypes.length != givenArgs.length) {
+            return false;
+        }
+        for (int i = 0; i < paramTypes.length; i++) {
+            if (!paramTypes[i].isInstance(givenArgs[i])) {
+                return false;
+            }
+        }
+        return true;
+    }
+
     /**
-     * @implNote If overridden, please cache any found non-inject constructors using {@link #putCachedNonInjectConstructor}.
+     * @implNote If overridden, please cache any found non-inject constructors using
+     *   {@link #putCachedNonInjectConstructor}.
      *
-     * @param clazz the {@link Class} in which to search for a constructor which does not have an <code>{@literal @}Inject</code>
-     *              annotation
+     * @param clazz the {@link Class} in which to search for a constructor which does
+     *              not have an <code>{@literal @}Inject</code> annotation.
      * @param constructorArgs the given constructor args
-     * @return the found non-inject constructor appropriate for the given constructor args, or {@code null} if no
-     * such constructor exists
+     * @return the found non-inject constructor appropriate for the given constructor args,
+     * or {@code null} if no such constructor exists
      * @param <T> the type
      */
     @SuppressWarnings("unchecked")
@@ -101,7 +199,7 @@ public abstract class AbstractInjectingObjectFactory implements ObjectFactory {
 
         final Constructor<?>[] constructors = this.cachedAllConstructors.computeIfAbsent(clazz, Class::getConstructors);
         for (Constructor<?> constructor : constructors) {
-            if (Arrays.equals(constructor.getParameterTypes(), types)) {
+            if (areArgsAssignable(constructor.getParameterTypes(), constructorArgs)) {
                 final Constructor<T> found = (Constructor<T>) constructor;
                 this.putCachedNonInjectConstructor(new CachedNonInjectConstructor<>(clazz, found, types));
                 return found;
@@ -156,42 +254,104 @@ public abstract class AbstractInjectingObjectFactory implements ObjectFactory {
     protected Parameter getCachedInjectParameter(Method setter) {
         return this.cachedSetterParameters.computeIfAbsent(setter, s -> {
             if (s.getParameterCount() != 1) {
-                throw new IllegalArgumentException("Setter " + s.getName() + " has a parameter count other than one (1)!");
+                throw new IllegalArgumentException(
+                        "Setter " + s.getName() + " has a parameter count other than one (1)!"
+                );
             }
             return s.getParameters()[0];
         });
     }
 
-    protected void injectSetter(Object target, Method setter) {
-        try {
-            setter.invoke(target, this.getSetterInjectArg(target.getClass(), setter, this.getCachedInjectParameter(setter)));
-        } catch (InvocationTargetException | IllegalAccessException e) {
-            throw new RuntimeException(e);
+    private @Nullable Object findInContext(CreateContext context, Class<?> type) {
+        for (final Resolved resolved : context.getAllResolved()) {
+            if (type.isAssignableFrom(resolved.type)) {
+                return resolved.object;
+            }
+        }
+        return null;
+    }
+
+    protected void injectSetter(CreateContext context, Object target, Method setter) {
+        final Parameter injectParam = this.getCachedInjectParameter(setter);
+        final Class<?> typeToInject = injectParam.getType();
+        final @Nullable Object fromContext = this.findInContext(context, typeToInject);
+
+        final Consumer<Object> setterAction = arg -> {
+            try {
+                setter.invoke(target, arg);
+            } catch (InvocationTargetException | IllegalAccessException e) {
+                throw new RuntimeException(e);
+            }
+        };
+
+        if (context.containsConstruction(typeToInject)) {
+            context.addDeferredSetterAction(typeToInject, setterAction);
+        } else {
+            final Object arg;
+            if (fromContext != null) {
+                arg = fromContext;
+            } else {
+                arg = this.getSetterInjectArg(context, target.getClass(), setter, injectParam);
+                context.getAllResolved().add(new Resolved(typeToInject, arg));
+            }
+            setterAction.accept(arg);
         }
     }
 
-    protected void injectSetters(Object target) {
-        this.getCachedSettersFor(target).forEach(setter -> this.injectSetter(target, setter));
+    protected void injectSetters(CreateContext context, Object target) {
+        this.getCachedSettersFor(target).forEach(setter -> this.injectSetter(context, target, setter));
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public <T> T createInstance(Class<T> clazz, Object... constructorArgs) {
-        final Constructor<T> constructor = this.findConstructor(clazz, constructorArgs);
-        final Object[] allArgs = this.createArgs(constructor, constructorArgs);
+    public <T> T createInstance(Class<T> type, Object... constructorArgs) {
+        final Constructor<T> constructor = this.findConstructor(type, constructorArgs);
+        final CreateContext context = new CreateContext(type);
+        final Object[] allArgs = this.createArgs(context, constructor, constructorArgs);
         try {
             final T instance = constructor.newInstance(allArgs);
-            this.injectSetters(instance);
+            context.getAllResolved().add(new Resolved(type, instance));
+            this.injectSetters(context, instance);
+            final List<Consumer<Object>> deferredSetterActions = context.getDeferredSetterActions();
+            context.popConstruction();
+            deferredSetterActions.forEach(setterAction -> setterAction.accept(instance));
             return instance;
         } catch (InvocationTargetException | IllegalAccessException | InstantiationException e) {
             throw new RuntimeException(e); // In the future, we might have an option to ignore exceptions
         }
     }
 
-    protected abstract Object[] createArgs(Constructor<?> constructor, Object[] constructorArgs);
+    protected <T> T createInstance(CreateContext context, Class<T> type, Object... givenArgs) {
+        final Constructor<T> constructor = this.findConstructor(type, givenArgs);
+        context.checkForCircularDependency(type);
+        context.pushConstruction(type);
+        final Object[] allArgs = this.createArgs(context, constructor, givenArgs);
+        try {
+            final T instance = constructor.newInstance(allArgs);
+            context.getAllResolved().add(new Resolved(type, instance));
+            this.injectSetters(context, instance);
+            final List<Consumer<Object>> deferredSetterActions = context.getDeferredSetterActions();
+            context.popConstruction();
+            deferredSetterActions.forEach(setterAction -> setterAction.accept(instance));
+            return instance;
+        } catch (InvocationTargetException | IllegalAccessException | InstantiationException e) {
+            throw new RuntimeException(e);
+        }
+    }
 
-    protected abstract Object getSetterInjectArg(Class<?> targetType, Method setter, Parameter toInject);
+    protected abstract Object[] createArgs(
+            CreateContext context,
+            Constructor<?> constructor,
+            Object[] constructorArgs
+    );
+
+    protected abstract Object getSetterInjectArg(
+            CreateContext context,
+            Class<?> targetType,
+            Method setter,
+            Parameter toInject
+    );
 
 }

src/main/java/groowt/util/di/AbstractRegistryObjectFactory.java

@@ -14,7 +14,8 @@ import java.util.function.Supplier;
 
 import static groowt.util.di.RegistryObjectFactoryUtil.orElseSupply;
 
-public abstract class AbstractRegistryObjectFactory extends AbstractInjectingObjectFactory implements RegistryObjectFactory {
+public abstract class AbstractRegistryObjectFactory extends AbstractInjectingObjectFactory
+        implements RegistryObjectFactory {
 
     public static abstract class AbstractBuilder<T extends DefaultRegistryObjectFactory> implements Builder<T> {
 
@@ -75,8 +76,8 @@ public abstract class AbstractRegistryObjectFactory extends AbstractInjectingObj
     }
 
     @Override
-    public void configureRegistry(Consumer<? super Registry> use) {
-        use.accept(this.registry);
+    public Registry getRegistry() {
+        return this.registry;
     }
 
     @Override

src/main/java/groowt/util/di/BindingUtil.java

@@ -27,6 +27,10 @@ public final class BindingUtil {
         return bc -> {};
     }
 
+    public static <T> KeyHolder<NamedRegistryExtension, String, T> named(String name, Class<T> type) {
+        return new SimpleKeyHolder<>(NamedRegistryExtension.class, type, name);
+    }
+
     private BindingUtil() {}
 
 }

src/main/java/groowt/util/di/DefaultRegistry.java

@@ -3,31 +3,58 @@ package groowt.util.di;
 import org.jetbrains.annotations.Nullable;
 
 import java.lang.annotation.Annotation;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
+import java.util.*;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Predicate;
 
 public class DefaultRegistry implements Registry {
 
-    protected record ClassKeyBinding<T>(Class<T> key, Binding<T> binding) {}
+    protected static class BindingContainer {
 
-    protected final Collection<ClassKeyBinding<?>> classBindings = new ArrayList<>();
+        private final Map<Class<?>, Binding<?>> bindings = new HashMap<>();
+
+        @SuppressWarnings("unchecked")
+        public <T> @Nullable Binding<T> get(Class<T> key) {
+            for (final var entry : bindings.entrySet()) {
+                if (entry.getKey().isAssignableFrom(key)) {
+                    return (Binding<T>) entry.getValue();
+                }
+            }
+            return null;
+        }
+
+        public <T> void put(Class<T> key, Binding<T> binding) {
+            this.bindings.put(key, binding);
+        }
+
+        public void remove(Class<?> key) {
+            this.bindings.remove(key);
+        }
+
+        public <T> void removeIf(Class<T> key, Predicate<? super Binding<T>> filter) {
+            if (filter.test(this.get(key))) {
+                this.bindings.remove(key);
+            }
+        }
+
+        public void clear() {
+            this.bindings.clear();
+        }
+
+    }
+
+    protected final BindingContainer bindingContainer = new BindingContainer();
     protected final Collection<RegistryExtension> extensions = new ArrayList<>();
 
     @Override
     public void removeBinding(Class<?> key) {
-        this.classBindings.removeIf(classKeyBinding -> classKeyBinding.key().equals(key));
+        this.bindingContainer.remove(key);
     }
 
-    @SuppressWarnings("unchecked")
     @Override
     public <T> void removeBindingIf(Class<T> key, Predicate<Binding<T>> filter) {
-        this.classBindings.removeIf(classKeyBinding ->
-                classKeyBinding.key().equals(key) && filter.test((Binding<T>) classKeyBinding.binding())
-        );
+        this.bindingContainer.removeIf(key, filter);
     }
 
     private <E extends RegistryExtension> List<E> getAllRegistryExtensions(Class<E> extensionType) {
@@ -117,18 +144,12 @@ public class DefaultRegistry implements Registry {
     public <T> void bind(Class<T> key, Consumer<? super BindingConfigurator<T>> configure) {
         final var configurator = new SimpleBindingConfigurator<>(key);
         configure.accept(configurator);
-        this.classBindings.add(new ClassKeyBinding<>(key, configurator.getBinding()));
+        this.bindingContainer.put(key, configurator.getBinding());
     }
 
-    @SuppressWarnings("unchecked")
     @Override
-    public @Nullable <T> Binding<T> getBinding(Class<T> key) {
-        for (final var classKeyBinding : this.classBindings) {
-            if (key.isAssignableFrom(classKeyBinding.key())) {
-                return (Binding<T>) classKeyBinding.binding();
-            }
-        }
-        return null;
+    public <T> @Nullable Binding<T> getBinding(Class<T> key) {
+        return this.bindingContainer.get(key);
     }
 
     private KeyBinder<?> findKeyBinder(Class<?> keyClass) {
@@ -189,7 +210,7 @@ public class DefaultRegistry implements Registry {
 
     @Override
     public void clearAllBindings() {
-        this.classBindings.clear();
+        this.bindingContainer.clear();
         for (final var extension : this.extensions) {
             if (extension instanceof KeyBinder<?> keyBinder) {
                 keyBinder.clearAllBindings();

src/main/java/groowt/util/di/DefaultRegistryObjectFactory.java

@@ -3,8 +3,6 @@ package groowt.util.di;
 import groowt.util.di.filters.FilterHandler;
 import groowt.util.di.filters.IterableFilterHandler;
 import org.jetbrains.annotations.Nullable;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
@@ -20,7 +18,8 @@ import static groowt.util.di.RegistryObjectFactoryUtil.*;
 
 public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory {
 
-    public static final class Builder extends AbstractRegistryObjectFactory.AbstractBuilder<DefaultRegistryObjectFactory> {
+    public static final class Builder
+            extends AbstractRegistryObjectFactory.AbstractBuilder<DefaultRegistryObjectFactory> {
 
         /**
          * Creates a {@code Builder} initialized with a {@link DefaultRegistry}, which is in-turn configured with a
@@ -74,7 +73,6 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
     }
 
     private static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
-    private static final Logger logger = LoggerFactory.getLogger(DefaultRegistryObjectFactory.class); // leave it for the future!
 
     private final Collection<FilterHandler<?, ?>> filterHandlers;
     private final Collection<IterableFilterHandler<?, ?>> iterableFilterHandlers;
@@ -107,7 +105,9 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
     @SuppressWarnings("unchecked")
     protected final @Nullable Object tryQualifiers(Parameter parameter) {
         final Class<?> paramType = parameter.getType();
-        final List<Annotation> qualifiers = RegistryObjectFactoryUtil.getQualifierAnnotations(parameter.getAnnotations());
+        final List<Annotation> qualifiers = RegistryObjectFactoryUtil.getQualifierAnnotations(
+                parameter.getAnnotations()
+        );
         if (qualifiers.size() > 1) {
             throw new RuntimeException("Parameter " + parameter + " cannot have more than one Qualifier annotation.");
         } else if (qualifiers.size() == 1) {
@@ -115,7 +115,9 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
             @SuppressWarnings("rawtypes")
             final QualifierHandler handler = this.getInSelfOrParent(
                     f -> f.findQualifierHandler(qualifier.annotationType()),
-                    () -> new RuntimeException("There is no configured QualifierHandler for " + qualifier.annotationType().getName())
+                    () -> new RuntimeException("There is no configured QualifierHandler for "
+                            + qualifier.annotationType().getName()
+                    )
             );
             final Binding<?> binding = handler.handle(qualifier, paramType);
             if (binding != null) {
@@ -165,21 +167,23 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
         }
     }
 
-    protected final Object resolveInjectedArg(Parameter parameter) {
+    protected final Object resolveInjectedArg(CreateContext context, Parameter parameter) {
         final Object qualifierProvidedArg = this.tryQualifiers(parameter);
         if (qualifierProvidedArg != null) {
             this.checkFilters(parameter, qualifierProvidedArg);
+            context.getAllResolved().add(new Resolved(parameter.getType(), qualifierProvidedArg));
             return qualifierProvidedArg;
         } else {
-            final Object created = this.get(parameter.getType());
+            final Object created = this.get(context, parameter.getType());
             this.checkFilters(parameter, created);
+            context.getAllResolved().add(new Resolved(parameter.getType(), created));
             return created;
         }
     }
 
-    protected final void resolveInjectedArgs(Object[] dest, Parameter[] params) {
+    protected final void resolveInjectedArgs(CreateContext context, Object[] dest, Parameter[] params) {
         for (int i = 0; i < params.length; i++) {
-            dest[i] = this.resolveInjectedArg(params[i]);
+            dest[i] = this.resolveInjectedArg(context, params[i]);
         }
     }
 
@@ -194,7 +198,7 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
 
     // TODO: when there is a null arg, we lose the type. Therefore this algorithm breaks. Fix this.
     @Override
-    protected Object[] createArgs(Constructor<?> constructor, Object[] givenArgs) {
+    protected Object[] createArgs(CreateContext context, Constructor<?> constructor, Object[] givenArgs) {
         final Class<?>[] paramTypes = constructor.getParameterTypes();
 
         // check no arg
@@ -218,7 +222,7 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
 
         if (givenArgs.length == 0) {
             // if no given args, then they are all injected
-            this.resolveInjectedArgs(resolvedArgs, allParams);
+            this.resolveInjectedArgs(context, resolvedArgs, allParams);
         } else if (givenArgs.length == paramTypes.length) {
             // all are given
             this.resolveGivenArgs(resolvedArgs, allParams, givenArgs, 0);
@@ -234,17 +238,23 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
             final Parameter[] givenParams = new Parameter[allParams.length - firstGivenIndex];
 
             System.arraycopy(allParams, 0, injectedParams, 0, injectedParams.length);
-            System.arraycopy(allParams, firstGivenIndex, givenParams, 0, allParams.length - firstGivenIndex);
+            System.arraycopy(
+                    allParams, firstGivenIndex, givenParams, 0, allParams.length - firstGivenIndex
+            );
 
-            this.resolveInjectedArgs(resolvedArgs, injectedParams);
+            this.resolveInjectedArgs(context, resolvedArgs, injectedParams);
             this.resolveGivenArgs(resolvedArgs, givenParams, givenArgs, firstGivenIndex);
         }
 
         return resolvedArgs;
     }
 
-    @SuppressWarnings("unchecked")
     private <T> T handleBinding(Binding<T> binding, Object[] constructorArgs) {
+        return this.handleBinding(binding, null, constructorArgs);
+    }
+
+    @SuppressWarnings("unchecked")
+    private <T> T handleBinding(Binding<T> binding, @Nullable CreateContext context, Object[] constructorArgs) {
         return switch (binding) {
             case ClassBinding<T>(Class<T> ignored, Class<? extends T> to) -> {
                 final Annotation scopeAnnotation = getScopeAnnotation(to);
@@ -253,12 +263,20 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
                     @SuppressWarnings("rawtypes")
                     final ScopeHandler scopeHandler = this.getInSelfOrParent(
                             f -> f.findScopeHandler(scopeClass),
-                            () -> new RuntimeException("There is no configured ScopeHandler for " + scopeClass.getName())
+                            () -> new RuntimeException(
+                                    "There is no configured ScopeHandler for " + scopeClass.getName()
+                            )
+                    );
+                    final Binding<T> scopedBinding = scopeHandler.onScopedDependencyRequest(
+                            scopeAnnotation, to, this
                     );
-                    final Binding<T> scopedBinding = scopeHandler.onScopedDependencyRequest(scopeAnnotation, to, this);
                     yield this.handleBinding(scopedBinding, constructorArgs);
                 } else {
-                    yield this.createInstance(to, constructorArgs);
+                    if (context != null) {
+                        yield this.createInstance(context, to, constructorArgs);
+                    } else {
+                        yield this.createInstance(to, constructorArgs);
+                    }
                 }
             }
             case ProviderBinding<T> providerBinding -> providerBinding.provider().get();
@@ -276,8 +294,8 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
     }
 
     @Override
-    protected Object getSetterInjectArg(Class<?> targetType, Method setter, Parameter toInject) {
-        return this.resolveInjectedArg(toInject);
+    protected Object getSetterInjectArg(CreateContext context, Class<?> targetType, Method setter, Parameter toInject) {
+        return this.resolveInjectedArg(context, toInject);
     }
 
     /**
@@ -293,7 +311,24 @@ public class DefaultRegistryObjectFactory extends AbstractRegistryObjectFactory
         if (parentResult != null) {
             return parentResult;
         } else {
-            throw new RuntimeException("No bindings for " + clazz + " with args " + Arrays.toString(constructorArgs) + ".");
+            throw new RuntimeException(
+                    "No bindings for " + clazz + " with args " + Arrays.toString(constructorArgs) + "."
+            );
+        }
+    }
+
+    protected <T> T get(CreateContext context, Class<T> type) {
+        final Binding<T> binding = this.searchRegistry(type);
+        if (binding != null) {
+            return this.handleBinding(binding, context, EMPTY_OBJECT_ARRAY);
+        }
+        final T parentResult = this.tryParent(type, EMPTY_OBJECT_ARRAY);
+        if (parentResult != null) {
+            return parentResult;
+        } else {
+            throw new RuntimeException(
+                    "No bindings for " + type + " with args " + Arrays.toString(EMPTY_OBJECT_ARRAY) + "."
+            );
         }
     }
 

src/main/java/groowt/util/di/NamedRegistryExtension.java

@@ -1,9 +1,3 @@
 package groowt.util.di;
 
-public interface NamedRegistryExtension extends RegistryExtension, KeyBinder<String>, QualifierHandlerContainer {
-
-    static <T> KeyHolder<NamedRegistryExtension, String, T> named(String name, Class<T> type) {
-        return new SimpleKeyHolder<>(NamedRegistryExtension.class, type, name);
-    }
-
-}
+public interface NamedRegistryExtension extends RegistryExtension, KeyBinder<String>, QualifierHandlerContainer {}

src/main/java/groowt/util/di/Registry.java

@@ -6,6 +6,7 @@ import java.util.function.Consumer;
 import java.util.function.Predicate;
 
 public interface Registry extends ExtensionContainer, QualifierHandlerContainer, ScopeHandlerContainer {
+
     <T> void bind(Class<T> key, Consumer<? super BindingConfigurator<T>> configure);
     @Nullable <T> Binding<T> getBinding(Class<T> key);
     void removeBinding(Class<?> key);

src/main/java/groowt/util/di/RegistryObjectFactory.java

@@ -1,5 +1,7 @@
 package groowt.util.di;
 
+import groovy.lang.Closure;
+import groovy.lang.DelegatesTo;
 import groowt.util.di.filters.FilterHandler;
 import groowt.util.di.filters.IterableFilterHandler;
 import jakarta.inject.Provider;
@@ -16,13 +18,38 @@ import java.util.function.Consumer;
 public interface RegistryObjectFactory extends ObjectFactory {
 
     interface Builder<T extends RegistryObjectFactory> {
+
         void configureRegistry(Consumer<? super Registry> configure);
+
+        default void configureRegistry(@DelegatesTo(Registry.class) Closure<?> configureClosure) {
+            this.configureRegistry(registry -> {
+                configureClosure.setDelegate(registry);
+                configureClosure.call();
+            });
+        }
+
         void addFilterHandler(FilterHandler<?, ?> handler);
+
         void addIterableFilterHandler(IterableFilterHandler<?, ?> handler);
+
         T build();
+
     }
 
-    void configureRegistry(Consumer<? super Registry> use);
+    Registry getRegistry();
+
+    default void configureRegistry(Consumer<? super Registry> use) {
+        use.accept(this.getRegistry());
+    }
+
+    default void configureRegistry(
+            @DelegatesTo(value = Registry.class)
+            Closure<?> configureClosure
+    ) {
+        final Registry registry = this.getRegistry();
+        configureClosure.setDelegate(registry);
+        configureClosure.call();
+    }
 
     <A extends Annotation> @Nullable ScopeHandler<A> findScopeHandler(Class<A> scopeType);
 

src/main/java/groowt/util/di/SingletonScopeHandler.java

@@ -1,8 +1,9 @@
 package groowt.util.di;
 
+import jakarta.inject.Provider;
 import jakarta.inject.Singleton;
 
-import static groowt.util.di.BindingUtil.toSingleton;
+import static groowt.util.di.BindingUtil.toLazySingleton;
 
 public final class SingletonScopeHandler implements ScopeHandler<Singleton> {
 
@@ -19,12 +20,22 @@ public final class SingletonScopeHandler implements ScopeHandler<Singleton> {
             RegistryObjectFactory objectFactory
     ) {
         final Binding<T> potentialBinding = this.owner.getBinding(dependencyClass);
-        if (potentialBinding != null) {
-            return potentialBinding;
-        } else {
-            this.owner.bind(dependencyClass, toSingleton(objectFactory.createInstance(dependencyClass)));
-            return this.owner.getBinding(dependencyClass);
-        }
+        return switch (potentialBinding) {
+            case ClassBinding<T>(Class<T> from, Class<? extends T> to) -> {
+                this.owner.bind(from, toLazySingleton(() -> objectFactory.createInstance(to)));
+                yield this.owner.getBinding(from);
+            }
+            case ProviderBinding<T>(Class<T> from, Provider<? extends T> provider) -> {
+                this.owner.bind(from, toLazySingleton(provider::get));
+                yield this.owner.getBinding(from);
+            }
+            case SingletonBinding<T> singletonBinding -> singletonBinding;
+            case LazySingletonBinding<T> lazySingletonBinding -> lazySingletonBinding;
+            case null -> {
+                this.owner.bind(dependencyClass, toLazySingleton(() -> objectFactory.createInstance(dependencyClass)));
+                yield this.owner.getBinding(dependencyClass);
+            }
+        };
     }
 
     @Override

src/test/java/groowt/util/di/DefaultRegistryObjectFactoryTests.java

@@ -2,10 +2,10 @@ package groowt.util.di;
 
 import jakarta.inject.Inject;
 import jakarta.inject.Named;
+import jakarta.inject.Singleton;
 import org.junit.jupiter.api.Test;
 
 import static groowt.util.di.BindingUtil.*;
-import static groowt.util.di.NamedRegistryExtension.named;
 import static org.junit.jupiter.api.Assertions.*;
 
 public class DefaultRegistryObjectFactoryTests {
@@ -167,4 +167,109 @@ public class DefaultRegistryObjectFactoryTests {
         assertEquals("Hello, World!", greeter.greet());
     }
 
+    public static final class GreeterDependency {
+
+        private GreeterDependencyUser greeter;
+
+        @Inject
+        public void setGreeter(GreeterDependencyUser greeter) {
+            this.greeter = greeter;
+        }
+
+        public String filterGreeting() {
+            return this.greeter.getGreeting().toUpperCase();
+        }
+
+    }
+
+    public static final class GreeterDependencyUser implements Greeter {
+
+        private final GreeterDependency greeterDependency;
+
+        @Inject
+        public GreeterDependencyUser(GreeterDependency greeterDependency) {
+            this.greeterDependency = greeterDependency;
+        }
+
+        @Override
+        public String greet() {
+            return this.greeterDependency.filterGreeting();
+        }
+
+        public String getGreeting() {
+            return "hello, world!";
+        }
+
+    }
+
+    @Test
+    public void injectedDeferred() {
+        final var b = DefaultRegistryObjectFactory.Builder.withDefaults();
+        b.configureRegistry(r -> {
+            r.bind(GreeterDependencyUser.class, toSelf());
+            r.bind(GreeterDependency.class, toSelf());
+        });
+        final var f = b.build();
+        final var g = f.get(GreeterDependencyUser.class);
+        assertEquals("HELLO, WORLD!", g.greet());
+    }
+
+    public static final class NoInjectGreeter implements Greeter {
+
+        private final String greeting;
+
+        public NoInjectGreeter(String greeting) {
+            this.greeting = greeting;
+        }
+
+        @Override
+        public String greet() {
+            return this.greeting;
+        }
+
+    }
+
+    @Test
+    public void noInjectFoundViaGet() {
+        final var b = DefaultRegistryObjectFactory.Builder.withDefaults();
+        b.configureRegistry(r -> {
+            r.bind(NoInjectGreeter.class, toSelf());
+        });
+        final var f = b.build();
+        final var g = f.get(NoInjectGreeter.class, "Given Greeting");
+        assertEquals("Given Greeting", g.greet());
+    }
+
+    @Test
+    public void noInjectFindViaCreate() {
+        final var b = DefaultRegistryObjectFactory.Builder.withDefaults();
+        b.configureRegistry(r -> {
+            r.bind(NoInjectGreeter.class, toSelf());
+        });
+        final var f = b.build();
+        final var g = f.createInstance(NoInjectGreeter.class, "Given Greeting");
+        assertEquals("Given Greeting", g.greet());
+    }
+
+    @Singleton
+    public static final class SingletonGreeter implements Greeter {
+
+        @Override
+        public String greet() {
+            return "Hello, World!";
+        }
+
+    }
+
+    @Test
+    public void singletonDoesNotOverflow() {
+        final var b = DefaultRegistryObjectFactory.Builder.withDefaults();
+        b.configureRegistry(r -> {
+            r.bind(SingletonGreeter.class, toSelf());
+        });
+        final var f = b.build();
+        final var g = f.get(SingletonGreeter.class);
+        assertEquals("Hello, World!", g.greet());
+    }
+
 }