Gets the rtm ws_host and user information

        Returns:
            None if request failed,
            else a dict containing "user"(User) and "ws_host"

def start(self):
        """Gets the rtm ws_host and user information

        Returns:
            None if request failed,
            else a dict containing "user"(User) and "ws_host"
        """
        resp = self.post('start')

        if resp.is_fail():
            return None
        if 'result' not in resp.data:
            return None

        result = resp.data['result']
        return {
            'user': result['user'],
            'ws_host': result['ws_host'],
        }