internal static void Delete(
     PointRegionQuadTree <object> tree,
     double x,
     double y)
 {
     PointRegionQuadTreeFilterIndexDelete <object> .Delete(x, y, tree);
 }
        public void TestGetSetRemove()
        {
            tree = PointRegionQuadTreeFactory <object> .Make(0, 0, 100, 100);

            Assert.IsNull(PointRegionQuadTreeFilterIndexGet <object> .Get(10, 20, tree));
            AssertCollectAll(tree, "");

            PointRegionQuadTreeFilterIndexSet <object> .Set(10, 20, "P0", tree);

            Assert.AreEqual("P0", PointRegionQuadTreeFilterIndexGet <object> .Get(10, 20, tree));
            AssertCollectAll(tree, "P0");

            PointRegionQuadTreeFilterIndexDelete <object> .Delete(10, 20, tree);

            Assert.IsNull(PointRegionQuadTreeFilterIndexGet <object> .Get(10, 20, tree));
            AssertCollectAll(tree, "");
        }