@Override
  @NotNull
  public PyCallExpression createCallExpression(final LanguageLevel langLevel, String functionName) {
    final PsiFile dummyFile = createDummyFile(langLevel, functionName + "()");
    final PsiElement child = dummyFile.getFirstChild();
    if (child != null) {
      final PsiElement element = child.getFirstChild();
      if (element instanceof PyCallExpression) {
        return (PyCallExpression)element;
      }
    }
    throw new IllegalArgumentException("Invalid call expression text " + functionName);
  }
@Override
  @NotNull
  public PyCallExpression createCallExpression(final LanguageLevel langLevel, String functionName)