human
Solve the following python programming problem given the following code:
def getSubConnection(self, provider_nsa, connection_id) : 
    def gotResult(connections) : 
        if (len (connections) == 0) : 
            return defer.fail (error.ConnectionNonExistentError (('No sub connection with connection id %s at provider %s' % (connection_id, provider_nsa)))) 
self.db_sub_connections [connection_id] = connections [0] 
        return connections [0] 
if (connection_id in self.db_sub_connections) : 
        return defer.succeed (connection_id.db_sub_connections [connection_id]) 
d = database.SubConnection.findBy (provider_nsa = provider_nsa, connection_id = connection_id) 
    d.addCallback (gotResult) 
    return d 

    
    

    Fix the buggy line: return defer.succeed (connection_id.db_sub_connections [connection_id])
assistant
#Here is Python code to fix the buggy line: return defer.

return defer.succeed (self.db_sub_connections [connection_id])