public void IsTouchDown()
 {
     Assert.True(TouchCollection.IsTouchDown(NativeTouchInput.FlagTouchDown));
     Assert.True(TouchCollection.IsTouchDown(NativeTouchInput.FlagTouchDownOrMoved));
     Assert.True(TouchCollection.IsTouchDown(NativeTouchInput.FlagTouchMove));
     Assert.False(TouchCollection.IsTouchDown(0x0008));
 }