code: function(res) {
          var bottomRight = new OpenLayers.Geometry.Point(
              this.maxExtent.right,
              this.maxExtent.bottom);
          return this.getContainingTileCoords(bottomRight, res);
      }
docs: Method: getLowerRightTileCoord
  Calculates the x/y pixel corresponding to the position
  of the lower right tile for the given resolution.
  
  Parameters:
  res - {Float} The resolution for which to compute the extent.
  
  Returns:
  {<OpenLayers.Pixel>} The x/y pixel corresponding to the position
  of the lower right tile for the given resolution.