TGRTimeline.m

- (BOOL)loadNewTweetsWithCompletionHandler:(void (^)(NSError *error))completionHandler
{
    if (self.loading) {
        return NO;
    }
    
    SLRequest *request = [self requestForNewTweets];
    [self loadTweetsWithRequest:request completionHandler:completionHandler];
    
    return YES;
}

- (BOOL)loadOldTweetsWithCompletionHandler:(void (^)(NSError *error))completionHandler
{
    if (self.loading) {
        return NO;
    }
    
    SLRequest *request = [self requestForOldTweets];
    [self loadTweetsWithRequest:request completionHandler:completionHandler];
    
    return YES;
}