assertEquals(
"1: r120-0-1:20 r130-0-1:30; " +
"2: r200-0-2:10 r300-0-2:30; ", comp.toString());
assertEquals(1, comp.compare(r1c1, r1c2));
assertEquals(1, comp.compare(r2c1, r2c2));
assertEquals(-1, comp.compare(r3c1, r3c2));
// reverse
assertEquals(-1, comp.compare(r1c2, r1c1));
assertEquals(-1, comp.compare(r2c2, r2c1));
assertEquals(1, comp.compare(r3c2, r3c1));