private final GroovySourceDirectorySet groovy;
    private final SourceDirectorySet allGroovy;

    @Inject
    public DefaultGroovySourceSet(String name, String displayName, ObjectFactory objectFactory) {
        this.groovy = createGroovySourceDirectorySet(name, displayName, objectFactory);
        allGroovy = objectFactory.sourceDirectorySet("all" + name, displayName + " Groovy source");
        allGroovy.source(groovy);

     *
     * @return The Groovy/Java source. Never returns null.
     */
    SourceDirectorySet getGroovy();

    /**
     * Configures the Groovy source for this set.
     *
     * <p>The given closure is used to configure the {@link SourceDirectorySet} which contains the Groovy source.
     *
     * @param configureClosure The closure to use to configure the Groovy source.

    private final static Map<String, String> LANGUAGES = new HashMap<>();

    private final SourceDirectorySet source;
    private boolean generated;
    private Task generatorTask;

    public AbstractLanguageSourceSet(ComponentSpecIdentifier identifier, Class<? extends BuildableComponentSpec> publicType, SourceDirectorySet source) {
        super(identifier, publicType);
        this.source = source;

    @Transient
    private
    val sourceDirectorySet: SourceDirectorySet = project.objects.sourceDirectorySet(
        kotlinModuleName,
        "Precompiled script plugin plugins"
    )

    @get:InputFiles
    @get:IgnoreEmptyDirectories
    @get:PathSensitive(PathSensitivity.RELATIVE)
    val sourceFiles: FileTree = sourceDirectorySet

    fun sourceDir(dir: Provider<Directory>) {

import org.gradle.api.file.SourceDirectorySet;
import org.gradle.api.internal.file.DefaultSourceDirectorySet;
import org.gradle.api.tasks.ScalaSourceDirectorySet;

import javax.inject.Inject;

public abstract class DefaultScalaSourceDirectorySet extends DefaultSourceDirectorySet implements ScalaSourceDirectorySet {
    @Inject

    @Inject
    public DefaultGroovySourceDirectorySet(SourceDirectorySet sourceDirectorySet, TaskDependencyFactory taskDependencyFactory) {
        super(sourceDirectorySet, taskDependencyFactory);
    }

import org.gradle.api.Incubating;
import org.gradle.api.file.SourceDirectorySet;
import org.gradle.language.base.LanguageSourceSet;

/**
 * A source set that exposes headers
 */
@Incubating
public interface HeaderExportingSourceSet extends LanguageSourceSet {
    /**
     * The headers as a directory set.
     */
    SourceDirectorySet getExportedHeaders();

    /**

 */

package org.gradle.api.tasks;

import org.gradle.api.file.SourceDirectorySet;

/**
 * A {@code ScalaSourceDirectorySet} defines the properties and methods added to a {@link org.gradle.api.tasks.SourceSet} by the {@code ScalaPlugin}.
 *
 * @since 7.1
 */
public interface ScalaSourceDirectorySet extends SourceDirectorySet {

        override val kotlinSourceDirectorySet: SourceDirectorySet
            get() = project.sourceSets["main"].kotlin
    }
}


val Project.kotlinDslPluginOptions: KotlinDslPluginOptions
    get() = extensions.getByType()


private
val Project.sourceSets: SourceSetContainer
    get() = extensions.getByType()


private
val SourceSet.kotlin: SourceDirectorySet

        and: "has at least one header exporting source set"
        final headerDir = tmpDir.createDir("headerDir")
        def headerDirSet = Stub(SourceDirectorySet) {
            getSrcDirs() >> [headerDir]
        }
        def sourceDirSet = Stub(SourceDirectorySet) {
            getFiles() >> [tmpDir.createFile("input.src")]
        }
        def sourceSet = Stub(HeaderExportingSourceSet) {