void smoothScrollTo(int x, int y) {
        smoothScrollTo(x, y, 0);
    }
Like {@link View#scrollBy}, but scroll smoothly instead of immediately.

@param x the number of pixels to scroll by on the X axis
@param y the number of pixels to scroll by on the Y axis
dkplayer-sample/src/main/java/xyz/doikki/dkplayer/widget/VerticalViewPager.java