ios - check for specific gesture recognizer -

i have uipageviewcontroller contains vcs. in pageviewcontroller can swipe left, right change vcs. everytime animation finish add gesturerecognizer it. question how check view have specific recognizer or not? need code this:

if check view has specific recognizer == false {  add recognizer }else{ skip. } 

i doing because have sidebarmenu. when sidebarmenu appears want add gesture current index pagecontentviewcontroller. so, code works fine, dont want add gesture everytime animation finishes.

i adding code. problem gestures created in other class(not current). first creating instance of class keep gestures:

let transtionmanger = transitionmanger() 

after add var of class named exitpangesture:

pagecontentviewcontroller.view.addgesturerecognizer(transtionmanger.exitpangesture3) 

the problem add everytime view appears. want check existence of gesture before adding it. dont want add everytime.

is looking for? please see comments explanation:

// if gesture recogniser added view (change view view want test)       if let recognizers = view.gesturerecognizers {             gr in recognizers {                 // check uipangesturerecognizer can check 1 need                 if let grecognizer = gr as? uipangesturerecognizer {                     println("gesture recognizer found")                 }             }         }