@Nullable
  private static String getMainDocumentation(PsiElement elem) {
    final VirtualFile helpFile = getHelpFile(elem);
    if (helpFile != null) {
      try {
        return VfsUtilCore.loadText(helpFile);
      }
      catch (IOException ignored) {
      }
    }
    return null;
  }
@Nullable
  private static String getMainDocumentation(PsiElement elem)