code: Map buildPageParamMap(Integer row, Integer pageSize) {
          HashMap map = new HashMap();
          if(row != null && row.intValue() != DEFAULT_ROW)
              map.put(PARAM_KEY_ROW, new String[]{encodeRow(row.intValue())});
  
          /* only encode the page size if it is not equal to the default page size for this data grid
          
             for example, if a data grid's default page size is 20 but is set somehow by the application
             to be 50, the default will read 20 but overridden pageSize value should be encoded in the URL
           */
          if(pageSize != null && pageSize.intValue() != _state.getPagerModel().getDefaultPageSize())
              map.put(PARAM_KEY_PAGE_SIZE, new String[]{encodePageSize(pageSize.intValue())});
  
          return map;
      }
docs: Build the URL parameter map given a current row and page size.  Note, the query parameters returned
  here are <b>not</b> URL encoded.  The map contains key / value pairs as (String, String[]).
  @param row the current row
  @param pageSize the current page size
  @return a map containing the pager query parameters