NIN filter expression returns "true" when element doesn't exist in the json

[wildMythicWest]

If we have some data
Map<String, Object> check = new HashMap<String, Object>(); check.put("item", 3); check.put("null_item", null);

and we use this filter
filter(where("not_existent_item").nin(3)).apply(createPredicateContext(check))
I expect to get false because no such element exists.
Instead the filter returns true.

If this is expected behavior, is it possible to add strict mode for filter expression matching so that if the element in the expression is not present the evaluator throws an exception?