@Override
  @NotNull
  public Collection<AbstractTreeNode<?>> getChildren() {
    Module module = getValue();
    if (module == null || module.isDisposed()) {  // module has been disposed
      return Collections.emptyList();
    }

    final List<VirtualFile> contentRoots = ProjectViewDirectoryHelper.getInstance(myProject).getTopLevelModuleRoots(module, getSettings());
    return ProjectViewDirectoryHelper.getInstance(myProject).createFileAndDirectoryNodes(contentRoots, getSettings());
  }
@Override
  @NotNull
  public Collection<AbstractTreeNode<?>> getChildren()