:param username:
        :return: a tuple (realname, email) if the user can be found, None else

def get_user_info(self, username):
        """
        :param username:
        :return: a tuple (realname, email) if the user can be found, None else
        """
        info = self.get_users_info([username])
        return info[username] if info is not None else None