human
Solve the following python programming problem given the following code:
def acquire(self) : 
    '
        Acquire a connection from the Pool

        :returns: Future -
            :py:class:`asyncio.Future`, :py:class:`trollius.Future`, or
            :py:class:`tornado.concurrent.Future`
        ' 
    future = self._future_class () 
    if self._pool : 
        while self._pool : 
            conn = self._pool.popleft () 
            if (not conn.closed) : 
                pool_logger.debug ('Reusing connection: {}'.format (conn)) 
                future.set_result (conn) 
                self._acquired.add (future) 
                break 
else : 
                pool_logger.debug ('Discarded closed connection: {}'.format (conn)) 
else : 
        if (self.size < self.maxsize) : 
            self._acquiring += 1 
            conn_future = self.graph.connect (force_release = self._force_release, pool = self) 
            def cb(f) : 
                try : 
                    conn = f.result () 
except Exception as e : 
                    future.set_exception (e) 
else : 
                    pool_logger.debug ('Got new connection {}'.format (conn)) 
                    self._acquired.add (conn) 
                    future.set_result (conn) 
finally : 
                    self._acquiring -= 1 
conn_future.add_done_callback (cb) 
else : 
            pool_logger.debug ('Waiting for available conn on future: {}...'.format (future)) 
            self._waiters.append (future) 
return future 

    
    

    Fix the buggy line: self._acquired.add (future)
assistant
#Here is Python program to fix the buggy line: self.

self._acquired.add (conn)