@Nullable
  protected PsiElement replaceExpression(PsiElement expression, PyExpression newExpression, IntroduceOperation operation) {
    PyExpressionStatement statement = PsiTreeUtil.getParentOfType(expression, PyExpressionStatement.class);
    if (statement != null) {
      if (statement.getExpression() == expression && expression.getUserData(PyReplaceExpressionUtil.SELECTION_BREAKS_AST_NODE) == null) {
        statement.delete();
        return null;
      }
    }
    return PyReplaceExpressionUtil.replaceExpression(expression, newExpression);
  }
@Nullable
  protected PsiElement replaceExpression(PsiElement expression, PyExpression newExpression, IntroduceOperation operation)