public void testRemove_nullAbsent() {
    assertEquals(0, getMultiset().remove(null, 2));
  }

  @CollectionFeature.Require(value = SUPPORTS_REMOVE, absent = ALLOWS_NULL_QUERIES)
  public void testRemove_nullForbidden() {
    assertThrows(NullPointerException.class, () -> getMultiset().remove(null, 2));
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)