My xcode cant find IntWithUpperBound.... I am stuck -.-

import GameKit

struct FactModel {
    let facts =  [
        "Ants stretch when they wake up in the morning.",
        "Ostriches can run faster than horses.",
        "Olympic gold medals are actually made mostly of silver.",
        "You are born with 300 bones; by the time you are an adult you will have 206.",
        "It takes about 8 minutes for light from the Sun to reach Earth.",
        "Some bamboo plants can grow almost a meter in just one day.",
        "The state of Florida is bigger than England.",
        "Some penguins can leap 2-3 meters out of the water.",
        "On average, it takes 66 days to form a new habit.",
        "Mammoths still walked the Earth when the Great Pyramid was being built."
    ]

    func getRandomFact() -> String {
    let randomNumber = GKRandomSource.sharedRandom()


    }

}