     let arbitrary: () -> T
     let smaller: (T) -> T?
 }
+
+let numberOfIterations = 10
 
 func checkHelper<A>(_ arbitraryInstance: ArbitraryInstance<A>, _ property: @escaping (A) -> Bool, _ message: String) {
     for _ in 0..<numberOfIterations {

        return nil
    }
}

extension Int: Arbitrary {
    static func arbitrary() -> Int {

    print("\(message) passed tests \(numberOfIterations) times")
}

// Quick-check implementation

func check<A: Arbitrary>(_ message: String, _ property: @escaping (A) -> Bool) {
    let arbitraryInstance = ArbitraryInstance(arbitrary: A.arbitrary, smaller: { $0.smaller() })
    checkHelper(arbitraryInstance, property, message)
