assertThrows(IllegalArgumentException.class, () -> bf1.putAll(bf2));

    assertFalse(bf2.isCompatible(bf1));
    assertThrows(IllegalArgumentException.class, () -> bf2.putAll(bf1));
  }

  public void testPutAllWithSelf() {
    BloomFilter<Integer> bf1 = BloomFilter.create(integerFunnel(), 1);
    assertFalse(bf1.isCompatible(bf1));
    assertThrows(IllegalArgumentException.class, () -> bf1.putAll(bf1));
  }