@Nullable
  public SourceFolder getSourceFolder(@NotNull final VirtualFile file) {
    final ContentEntry contentEntry = getContentEntry();
    if (contentEntry == null) {
      return null;
    }
    for (SourceFolder sourceFolder : contentEntry.getSourceFolders()) {
      final VirtualFile f = sourceFolder.getFile();
      if (f != null && f.equals(file)) {
        return sourceFolder;
      }
    }
    return null;
  }
@Nullable
  public SourceFolder getSourceFolder(@NotNull final VirtualFile file)