// However, currently it is not easy to determine whether this is the case so assume that all transforms
            // have changing inputs
            FileCollectionStructureVisitor.VisitType.NoContents
        } else {
            FileCollectionStructureVisitor.VisitType.Visit
        }
    }

    override fun requireArtifactFiles(): Boolean {
        return true
    }

                visitor.accept(fileTree);
            }
        });
    }

    @Override
    protected void visitContents(FileCollectionStructureVisitor visitor) {
        collection.visitStructure(new FileCollectionStructureVisitor() {
            final Set<File> seen = new HashSet<>();

            @Override
            public void visitCollection(Source source, Iterable<File> contents) {

     * Visits the structure of this collection, that is, zero or more atomic sources of files.
     *
     * <p>The implementation should call the most specific methods on {@link FileCollectionStructureVisitor} that it is able to.</p>
     */
    void visitStructure(FileCollectionStructureVisitor visitor);

    /**
     * Returns the display name of this file collection. Used in log and error messages.
     *
     * @return the display name
     */

import org.gradle.api.internal.file.FileCollectionBackedFileTree
import org.gradle.api.internal.file.FileCollectionFactory
import org.gradle.api.internal.file.FileCollectionInternal
import org.gradle.api.internal.file.FileCollectionStructureVisitor
import org.gradle.api.internal.file.FileOperations
import org.gradle.api.internal.file.FileTreeInternal
import org.gradle.api.internal.file.FilteredFileTree
import org.gradle.api.internal.file.archive.TarFileTree

        return displayName;
    }

    @Override
    public Set<File> getFiles() {
        return ImmutableSet.of();
    }

    @Override
    protected void visitContents(FileCollectionStructureVisitor visitor) {
    }

    @Override
    public FileTreeInternal getAsFileTree() {
        return new EmptyFileTree(FileTreeInternal.DEFAULT_TREE_DISPLAY_NAME);
    }

    @Override