The documentation for NotesJSONElement is incomplete. It states the values for the 'type' property can be Jsonelem_type_array, Jsonelem_type_boolean, Jsonelem_type_empty, Jsonelem_type_number, Jsonelem_type_object, Jsonelem_type_string
But vor the property 'value', only the types String, Boolean, Integer, Long, Double are possible. There are type posible for which the value is undefined.
Please amend the documentation.