Implement negation of query filter closer to underlying API. Previously andNot() negated the whole filter and it's usage in IsUnique was actually a misunderstanding. Having not() as in javax.persistence.criteria.Predicate seems to be more intuitive for negating the whole filter and more flexible.

{
    "stammdaten.datensatz_erzeuger": [{
        "id": 1000,
        "bezeichnung": "Testbezeichnung",
        "netzbetreiber_id": "06",
        "mst_id": "06010",
        "datensatz_erzeuger_id": "06"
    }]
}