public static NullableDataSourceInvertedInvertedStandard <OptionalCollectionStateValidator <TValue>, UniqueValidator <TValue>, ItemCountValidator <TValue>, CustomValidator <TValue[]>, TValue[]> Assert <TValue>(this NullableDataSourceInvertedInverted <OptionalCollectionStateValidator <TValue>, UniqueValidator <TValue>, ItemCountValidator <TValue>, TValue[]> source, string description, Func <TValue[], bool> validator) => source.Add(new CustomValidator <TValue[]>(description, validator));
