ResultSet
Explanation
This is one of the base parameters for the API.
It is mostly used by the server to send some information, but client should be using List instead. The ResultSet is used as a return parameter when a ListInfo object is provided as an input parameter.
The difference between List and ResultSet is that result provides a subset of a possible List of result. A ResultSet object also has a total items field that provides the number of elements that could have been returned if instead of a ResultSet we had returned a List.
Json example