如何使用python Mock验证成员变量是否已设置？

from unittest.mock import Mock

class MyClass:
    def __init__(self):
        self.my_variable = None

    def set_variable(self, value):
        self.my_variable = value

    def do_something(self):
        if self.my_variable is None:
            # do something if variable is not set
            pass
        else:
            # do something if variable is set
            pass

# 创建一个Mock对象
my_mock = Mock()

# 创建一个MyClass对象，并将my_variable设置为my_mock
my_class = MyClass()
my_class.set_variable(my_mock)

# 验证my_variable是否已设置
my_class.do_something()
my_mock.assert_called_with()