code: protected JSONObject dataItemAt(JSONObject jsonItem,  RequestType requestType, ActionType action) {
          JSONObject eachRow = null;    
          if (requestType == RequestType.GROUPBY) {
              eachRow = jsonItem.getJSONObject("event");
          } else if (requestType == RequestType.TIMESERIES) {
              eachRow = jsonItem.getJSONObject("result");
          } else if (requestType == RequestType.TOPN) {
              eachRow = jsonItem;
          } 
          return eachRow;
      }
docs: Extract the data item from json(based on the request type) and also fill in the
  headers as a side affect.
  @param jsonItem
  @param requestType
  @param action
  @return