Hi Yonik, it seams we have another one nobody uses :)
this fails: public void testFlipRange() { OpenBitSet b1 = new OpenBitSet(100); b1.set(0); b1.set(4); b1.set(5); b1.set(9); b1.flip(0,3); assertFalse(b1.get(0)); assertTrue(b1.get(1)); assertTrue(b1.get(2)); } but if you flip(0,5) it works cheers, e.