@Test(expected = ExecutionException.class)
 public void testRemoveAsyncOperationThrowsExceptionWhenQuorumSizeNotMet() throws Exception {
   Future<Boolean> foo = cache4.removeAsync(1);
   foo.get();
 }
 @Test
 public void testRemoveAsyncOperationSuccessfulWhenQuorumSizeMet() throws Exception {
   Future<Boolean> foo = cache1.removeAsync(1);
   foo.get();
 }