@Override
 @Test
 public void asUnmodifiable() {
   super.asUnmodifiable();
   Assert.assertSame(this.map, this.map.asUnmodifiable());
 }
 @Override
 @Test(expected = UnsupportedOperationException.class)
 public void putDuplicateWithRemovedSlot() {
   String collision1 = AbstractMutableObjectBooleanMapTestCase.generateCollisions().getFirst();
   this.getEmptyMap().put(collision1, true);
 }