 @IBDesignable
 open class RangeSlider: UIControl {
     
-    public typealias BeganEditingCallback = () -> Void
+    public typealias BeganTrackingCallback = () -> Void
     public typealias ValueChangedCallback = (_ minValue: Int, _ maxValue: Int) -> Void
     public typealias ValueFinishedChangingCallback = (_ minValue: Int, _ maxValue: Int) -> Void
     public typealias MinValueDisplayTextGetter = (_ minValue: Int) -> String?

    fileprivate var beginTrackLocation = CGPoint.zero
    fileprivate var rangeValues = Array(0...100)

    fileprivate var beganEditingCallback: BeganEditingCallback?
    fileprivate var valueChangedCallback: ValueChangedCallback?
    fileprivate var valueFinishedChangingCallback: ValueFinishedChangingCallback?
    fileprivate var minValueDisplayTextGetter: MinValueDisplayTextGetter?

        updateLayerFrames()
    }
    
    open func setBeganTrackingCallback(_ callback: BeganTrackingCallback?) {
        self.beganTrackingCallback = callback
    }
    
    open func setValueChangedCallback(_ callback: ValueChangedCallback?) {
