Dispatch_after
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) { () -> Void in
}
repetitive code
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) { () -> Void in
}