@Test
  void isNot() {
    repository.insert(generator.get().withId("id1").withValue(true).withNullable(false).withBoxed(Boolean.TRUE).withOptional(Optional.of(false)));
    repository.insert(generator.get().withId("id2").withValue(false).withNullable(null).withBoxed(Boolean.FALSE).withOptional(Optional.empty()));


    ids(holder.value.isNot(true)).isOf("id2");
    ids(holder.value.isNot(false)).isOf("id1");

    ids(holder.nullable.isNot(true)).notEmpty();
    ids(holder.nullable.isNot(false)).not().has("id1");
  }
Check for empty results on empty backend
criteria/common/test/org/immutables/criteria/typemodel/BooleanTemplate.java