@Test(expected = IllegalArgumentException.class)
public void testTooManyMutations() {

  MutateRowsRequest.Entry.Builder bigRequest = createRequestEntry().toBuilder();
  bigRequest.addAllMutations(
      Collections.nCopies(
          (int) BulkMutation.MAX_NUMBER_OF_MUTATIONS, bigRequest.getMutations(0)));
  underTest.add(bigRequest.build());
}