assertSame(r1 == r2, b1, b2, "nodeCount");
if (false) assertSame(r1 == r2, b1, b2, "nodeCount");
        public int nodeCount() {            int r1 = b1.nodeCount();            int r2 = b2.nodeCount();            assertSame(r1 == r2, b1, b2, "nodeCount");            return r1;        }