     return c / 2 * (sqrt(1 - t * t) + 1) + b
 }
 
-func DKKeyframeAnimationFunctionEaseInElastic(var t: Double, b: Double, c: Double, d: Double) -> Double {
+func DKKeyframeAnimationFunctionEaseInElastic(t: Double, b: Double, c: Double, d: Double) -> Double {
     var s = 1.70158
     var p = 0.0
     var a = c

    }
}

func DKKeyframeAnimationFunctionEaseInBack(var t: Double, b: Double, c: Double, d: Double) -> Double {
    let s = 1.70158
    t /= d
    return c * t * t * ((s + 1) * t - s) + b;
}

func DKKeyframeAnimationFunctionEaseOutBack(var t: Double, b: Double, c: Double, d: Double) -> Double {
    let s = 1.70158
    t = t / d - 1
    return c * (t * t * ((s + 1) * t + s) + 1) + b;
}

func DKKeyframeAnimationFunctionEaseInOutBack(var t: Double, b: Double, c: Double, d: Double) -> Double {
    var s = 1.70158
    t /= d / 2

    if t < 1 {
        s *= 1.525

    }
}

func DKKeyframeAnimationFunctionEaseInQuint(t: Double, b: Double, c: Double, d: Double) -> Double {
    let t = t / d
    return c * t * t * t * t * t + b;
}

func DKKeyframeAnimationFunctionEaseOutQuint(t: Double, b: Double, c: Double, d: Double) -> Double {
    let t = t / d - 1
    return c * (t * t * t * t * t + 1) + b;
}

func DKKeyframeAnimationFunctionEaseInOutQuint(t: Double, b: Double, c: Double, d: Double) -> Double {
    var t = t / (d / 2)
    if t < 1 {
        return c / 2 * t * t * t * t * t + b;
    } else {
