public void peakPrevious(boolean once) {
        if (mCurrentPageIndex > 0) {
            peak(false, once);
        }
    }
Hint that there is a previous page will do nothing if there is no
previous page

@param once if true, only peak once. else peak until user interacts with
            view
app/src/main/java/home/smart/fly/animations/customview/flipview/FlipView.java