class GridLayoutManager extends LinearLayoutManager {

    public void setSpanCount(int spanCount) {
        if (spanCount == mSpanCount) {
            return;
        }
        mPendingSpanCountChange = true;
        if (spanCount < 1) {
            throw new IllegalArgumentException("Span count should be at least 1. Provided "
                    + spanCount);
        }
        mSpanCount = spanCount;
        mSpanSizeLookup.invalidateSpanIndexCache();
        requestLayout();
    }

    public  GridLayoutManager(Context context, AttributeSet attrs, int defStyleAttr,
                             int defStyleRes);
    public  GridLayoutManager(Context context, int spanCount);
    public  GridLayoutManager(Context context, int spanCount,
            @RecyclerView.Orientation int orientation, boolean reverseLayout);

}