@Override
  public PsiElement addBefore(@NotNull PsiElement psiElement, PsiElement beforeThis) throws IncorrectOperationException {
    checkPyExpression(psiElement);
    return PyElementGenerator.getInstance(getProject()).insertItemIntoList(this, null, (PyExpression)psiElement);
  }
@Override
  public PsiElement addBefore(@NotNull PsiElement psiElement, PsiElement beforeThis)