}

    @Override
    public FileTreeInternal treeOf(List<? extends FileTreeInternal> fileTrees) {
        if (fileTrees.isEmpty()) {
            return FileCollectionFactory.emptyTree();
        } else if (fileTrees.size() == 1) {
            return fileTrees.get(0);
        } else {
            return new DefaultCompositeFileTree(taskDependencyFactory, patternSetFactory, ImmutableList.copyOf(fileTrees));