Python3注释错误

Question

当我使用python3注释时

class UserBean(SerializationBean):

    # serial_field = {"account", "nick_name"}
    non_serial_field = {"password"}

    def __init__(self, account: str = None, password: str = None, nick_name: str = None, roommate: UserBean = None):
        super().__init__()
        self._account = account
        self._password = password
        self._nick_name = nick_name
        self._roommate = roommate

室友的注释会引发NameError：name＆＃39; UserBean＆＃39;没有定义 如何解决？