[op addCompletionHandler:^(MKNetworkOperation* completedOperation) {
        [completedOperation responseJSONWithCompletionHandler:^(id jsonObject) {
            msg.responseString = completedOperation.responseString;
            msg.output = jsonObject;
            [self checkCode:msg];
            if([completedOperation isCachedResponse]){
                NSLog(@"iscache:YES");
            }else{
                NSLog(@"iscache:NO");
            }
        }];
    } errorHandler:^(MKNetworkOperation *errorOp, NSError* error) {
        msg.error = error;
        [self failed:msg];
    }];

__unsafe_unretained Request *weakMsg = msg;
__unsafe_unretained Action *weakSelf = self;
[op addCompletionHandler:^(MKNetworkOperation* completedOperation) {
        [completedOperation responseJSONWithCompletionHandler:^(id jsonObject) {
            weakMsg.responseString = completedOperation.responseString;
            weakMsg.output = jsonObject;
            [weakSelf checkCode: weakMsg];
            if([completedOperation isCachedResponse]){
_
                NSLog(@"iscache:YES");
            }else{
                NSLog(@"iscache:NO");
            }
        }];
    } errorHandler:^(MKNetworkOperation *errorOp, NSError* error) {
        weakMsg.error = error;
        [weakSelf failed: weakMsg];
    }];