title: Rails active_model_serializer with pagination
body: <p>I'm using active_model_serializer. Now I want to serialize an object with pagination, should I do the pagination logic in the controller or in the serializer? </p>
  
  <p>If I choose to do the pagination in serializer, I need to pass the page_number and per_page to the serializer. How should I do that? My understanding is serializer only takes the model object. </p>