private static boolean isViewDescendantOf(View child, View parent) {
        if (child == parent) {
            return true;
        }

        final ViewParent theParent = child.getParent();
        return (theParent instanceof ViewGroup) && isViewDescendantOf((View) theParent, parent);
    }
Return true if child is a descendant of parent, (or equal to the parent).
app/src/main/java/home/smart/fly/animations/widget/NestedScrollView.java