code: @Override
      public Map<String, Object> constructTimeframeArgs() {
          Map<String, Object> timeframe = null;
  
          if (start != null && end != null) {
              Map<String, Object> absoluteTimeframe = new HashMap<String, Object>(3);
  
              absoluteTimeframe.put(KeenQueryConstants.START, start);
              absoluteTimeframe.put(KeenQueryConstants.END, end);
  
              timeframe = new HashMap<String, Object>(2);
              timeframe.put(KeenQueryConstants.TIMEFRAME, absoluteTimeframe);
  
              return timeframe;
          }
  
          return timeframe;
      }
docs: Construct the Timeframe map to send in the query.
  
  @return  the Timeframe Json map to send in the query.