import java.io.File;
import java.util.Collections;
import java.util.Set;
import java.util.function.Consumer;

final class EmptyFileTree extends AbstractFileTree {
    public static final FileTreeInternal INSTANCE = new EmptyFileTree(DEFAULT_TREE_DISPLAY_NAME);

    private final String displayName;

    public EmptyFileTree(String displayName) {
        this.displayName = displayName;
    }

    @Override

    }

    @Override
    protected void visitContents(FileCollectionStructureVisitor visitor) {
    }

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

    @Override
    public Optional<FileCollectionExecutionTimeValue> calculateExecutionTimeValue() {

    static FileTreeInternal emptyTree() {
        return EmptyFileTree.INSTANCE;
    }

    static FileTreeInternal emptyTree(String displayName) {
        if (FileTreeInternal.DEFAULT_TREE_DISPLAY_NAME.equals(displayName)) {
            return emptyTree();
        } else {
            return new EmptyFileTree(displayName);
        }
    }