import Foundation


protocol TrackingDelegate where Self: UIViewController {
    func test()
}


class Test: UIViewController { }


extension Test: TrackingDelegate {
    func test() {
        print(self)
    }
}


func methodUsedToTriggerTest(for controller: UIViewController) {
    if let infoProvider = controller as? TrackingDelegate {
        print("Run test")
        return infoProvider.test()
    }
}


print("Test started \(arc4random())")
let test = Test()
methodUsedToTriggerTest(for: test)
print("Test completed")

methodUsedToTriggerTest(for: test)

error: Execution was interrupted, reason: EXC_BAD_ACCESS (code=1, address=0x0).

print(self)