LJTimer

- (void)startAt: (dispatch_time_t)delay seconds: (dispatch_time_t)seconds success: (void(^)(void))success progress: (void(^)(NSUInteger value))progress complete: (void(^)(void))complete;

- (void)suspend: (void(^)(void))complete;

- (void)resume:(void(^)(void))complete;

- (void)cancel;