     func pan(sender: AnyObject) {
         let pan = sender as! UIPanGestureRecognizer
         switch pan.state {
-        case .Began, .Changed:
+        case .Began:
+            upTimer?.invalidate()
+            upTimer = nil
+        case .Changed:
             if let window = Drop.window() {
-                removable = false
-                
                 let point = pan.translationInView(window)
                 let location = pan.locationInView(window)
                 

            constant: 100.0
        )
        self.addConstraint(heightConstraint)
    }
    
    required public init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
    
    func up() {
        Drop.up(self)
    }
    
    private func updateHeight() {

                    if let drop = drop { drop.layoutIfNeeded() }
                }, completion: nil
            )
        }
    }
    
