@Nullable
  public static PyAstStringLiteralExpression findDocStringExpression(@Nullable PyAstElement parent) {
    if (parent != null) {
      PsiElement seeker = PyPsiUtilsCore.getNextNonCommentSibling(parent.getFirstChild(), false);
      if (seeker instanceof PyAstExpressionStatement) seeker = PyPsiUtilsCore.getNextNonCommentSibling(seeker.getFirstChild(), false);
      if (seeker instanceof PyAstStringLiteralExpression) return (PyAstStringLiteralExpression)seeker;
    }
    return null;
  }
@Nullable
  public static PyAstStringLiteralExpression findDocStringExpression(@Nullable PyAstElement parent)