How to make my iphone vibrate twice when I click on a button?

I search to make vibrate twice my iphone when I click on a button (like a sms alert vibration)

With AudioServicesPlayAlertSound(SystemSoundID(kSystemSoundID_Vibrate)) I obtain just one normal vibration but I want two shorts :/.

#import <AudioToolbox/AudioServices.h>


AudioServicesPlayAlertSound(UInt32(kSystemSoundID_Vibrate))

This is the swift function...See this article for detailed description.