@Nullable
  public static PyExpression peelArgument(PyExpression expr) {
    while (expr instanceof PyParenthesizedExpression) expr = ((PyParenthesizedExpression)expr).getContainedExpression();
    if (expr instanceof PyKeywordArgument) expr = ((PyKeywordArgument)expr).getValueExpression();
    return expr;
  }
@Nullable
  public static PyExpression peelArgument(PyExpression expr)