import javax.inject.Inject;
import java.io.File;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.function.Consumer;

public abstract class DefaultSourceSetOutput extends CompositeFileCollection implements SourceSetOutput {
    private final ConfigurableFileCollection outputDirectories;
    private Object resourcesDir;

    private final ConfigurableFileCollection classesDirs;

package org.gradle.api.plugins.jvm.internal

import org.gradle.api.Task
import org.gradle.api.file.ConfigurableFileCollection
import org.gradle.api.file.SourceDirectorySet
import org.gradle.api.internal.tasks.DefaultSourceSetOutput
import org.gradle.api.tasks.SourceSet
import org.gradle.api.tasks.TaskProvider
import org.gradle.api.tasks.compile.JavaCompile

import static org.gradle.util.TestUtil.objectFactory

        variant.getAttributes().attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, objectFactory.named(LibraryElements.class, LibraryElements.RESOURCES));
        DefaultSourceSetOutput output = Cast.uncheckedCast(sourceSet.getOutput());
        DefaultSourceSetOutput.DirectoryContribution resourcesContribution = output.getResourcesContribution();
        if (resourcesContribution != null) {

    private final SourceDirectorySet resources;
    private final String displayName;
    private final SourceDirectorySet allSource;
    private final ClassDirectoryBinaryNamingScheme namingScheme;
    private DefaultSourceSetOutput output;

    @Inject
    public DefaultSourceSet(String name, ObjectFactory objectFactory) {
        this.name = name;

        sourceDirectorySet.getDestinationDirectory().convention(target.getLayout().getBuildDirectory().dir(sourceSetChildPath));

        DefaultSourceSetOutput sourceSetOutput = Cast.cast(DefaultSourceSetOutput.class, sourceSet.getOutput());
        sourceSetOutput.getClassesDirs().from(sourceDirectorySet.getDestinationDirectory()).builtBy(compileTask);

Accessors for org.gradle.api.internal.file.copy.DelegatingCopySpecInternal.fileMode don't use symmetrical @Nullable
Accessors for org.gradle.api.internal.tasks.DefaultSourceSetOutput.resourcesDir don't use symmetrical @Nullable
Accessors for org.gradle.api.internal.tasks.TaskStateInternal.outcome don't use symmetrical @Nullable

    @Override
    protected SourceSet doCreate(String name) {
        DefaultSourceSet sourceSet = instantiator.newInstance(DefaultSourceSet.class, name, objectFactory);
        sourceSet.setClasses(instantiator.newInstance(DefaultSourceSetOutput.class, sourceSet.getDisplayName(), taskDependencyFactory, fileResolver, fileCollectionFactory));
        return sourceSet;
    }

    @Override
    public TypeOf<?> getPublicType() {

import org.gradle.api.internal.artifacts.ConfigurationVariantInternal
import org.gradle.api.internal.artifacts.configurations.ConfigurationInternal
import org.gradle.api.internal.tasks.DefaultSourceSetOutput
import org.gradle.api.tasks.SourceSet
import org.gradle.api.tasks.TaskProvider
import org.gradle.api.tasks.compile.JavaCompile
import org.gradle.util.AttributeTestUtil

import org.gradle.api.internal.artifacts.configurations.UsageDescriber;
import org.gradle.api.internal.file.FileTreeInternal;
import org.gradle.api.internal.plugins.DslObject;
import org.gradle.api.internal.tasks.DefaultSourceSetOutput;
import org.gradle.api.internal.tasks.JvmConstants;
import org.gradle.api.internal.tasks.compile.CompilationSourceDirs;
import org.gradle.api.internal.tasks.compile.JavaCompileExecutableUtils;

    private DefaultSourceSet sourceSet(String name) {
        def s = TestUtil.newInstance(DefaultSourceSet, name, TestUtil.objectFactory(tmpDir.testDirectory))
        s.classes = TestUtil.newInstance(DefaultSourceSetOutput, s.displayName, taskDependencyFactory, fileResolver, fileCollectionFactory)
        return s
    }

    void hasUsefulDisplayName() {
        SourceSet sourceSet = sourceSet('int-test')
        expect: