code: public Map getQueryParams() {
          Map params = _codec.getExistingParams();
          Map newParams = new HashMap();
  
          addSortParams(newParams);
          addFilterParams(newParams);
          addPagerParams(newParams);
  
          params = mergeMaps(params, newParams);
          params = transformMap(params);
  
          return params;
      }
docs: <p>
  Get the query parameters for the currene state of the data grid.  The {@link Map} returned by this method
  will maintain the <i>current</i> state of the data grid and all of the associated URL parameters.  The
  {@link Map} contains key / value pairs of type String / String[].
  </p>
  @return the current URL and data grid state