Mockito.when（）。thenReturn（）和断言函数调用

Question

我是python的新手。在我当前的项目中，我正在编写如下的单元测试：

db_obj.fetch_cursor_records.return_value = create_mock_data() ##IN THIS LINE I AM 
## TRYING TO MOCK THE RETURN VALUE FROM fetch_cursor_records()

db_obj.fetch_cursor_records.assert_called_once() ## IN THIS LINE I AM TRYING TO ASSERT 
## THAT FETCH_CURSOR_RECORDS CALLED JUST ONCE 

upload_to_s3.assert_called_once_with(create_mock_data())## IN THIS LINE 
## I AM TRYING TO ASSERT THAT FETCH_CURSOR_RECORDS CALLED JUST ONCE WITH THE MOCK DATA

任何人都可以在同一指针上给出任何指针吗？