private void addChildrenFiles(@NotNull Set<? super PsiFile> psiFiles, DefaultMutableTreeNode parentNode, @NotNull List<? extends PsiFile> moduleFiles) {
    moduleFiles.sort(FILE_COMPARATOR);
    for (PsiFile file : moduleFiles) {
      final DefaultMutableTreeNode fileNode = createFileNode(file);
      parentNode.add(fileNode);
      psiFiles.add(file);
    }
  }
private void addChildrenFiles(@NotNull Set<? super PsiFile> psiFiles, DefaultMutableTreeNode parentNode, @NotNull List<? extends PsiFile> moduleFiles)