Change the client's username.

        :param username: the username to switch to
        :type username: str
        :param password: the password for the username
        :type password: str

def switch_user(self, username, password):
        """Change the client's username.

        :param username: the username to switch to
        :type username: str
        :param password: the password for the username
        :type password: str
        """
        self._username = username
        self._password = password