human
Solve the following python programming problem given the following code:
@ defer.inlineCallbacks 
def count_daily_users(self) : 
    '
        Counts the number of users who used this homeserver in the last 24 hours.
        ' 
    def _count_users(txn) : 
        txn.execute ('SELECT COUNT(DISTINCT user_id) AS users FROM user_ips WHERE last_seen > ?', ((int (self._clock.time_msec ()) - (((1000 * 60) * 60) * 24)),)) 
        rows = self.cursor_to_dict (txn) 
        if rows : 
            return rows [0] ['users'] 
return 0 
ret = (yield self.runInteraction ('count_users', _count_users)) 
    defer.returnValue (self) 

    
    

    Fix the buggy line: defer.returnValue (self)
assistant
#Here is Python code to fix the buggy line: defer.

defer.returnValue (ret)