class NestedScrollView extends FrameLayout implements NestedScrollingParent2,
        NestedScrollingChild2, ScrollingView {

    public void setFillViewport(boolean fillViewport) {
        if (fillViewport != mFillViewport) {
            mFillViewport = fillViewport;
            requestLayout();
        }
    }

    public  NestedScrollView(@NonNull Context context);
    public  NestedScrollView(@NonNull Context context, @Nullable AttributeSet attrs);
    public  NestedScrollView(@NonNull Context context, @Nullable AttributeSet attrs,
                            int defStyleAttr);

}