code: public BoxRequestsCollections.GetCollectionItems getItemsRequest(String id) {
          BoxRequestsCollections.GetCollectionItems request = new BoxRequestsCollections.GetCollectionItems(id, getCollectionItemsUrl(id), mSession);
          return request;
      }
docs: Gets a request that gets the items of a collection
  
  @param id id of collection to retrieve items of
  @return request to get a collections items