swift3 - อยากทราบวิธีการ Share UI ของอีกคลาสหนึ่งต้องเขียนยังไงครับ??

//Outside 1st class
protocol abc {
     func xyz()
}

//Inside 1st class
var delegate: abc?

//Inside 1st class on action
self.delegate.xyz()

//Inside 2nd class you want to perform method
extension 2nd: abc {
    func xyz(){
      //code 
   }
}

//Inside 2nd class where the instantiate process is performed
let obj = 2nd initialiser
obj.delegate = self