code: function(x, y) {
          if ( (x == null) || (y == null) ) {
              throw new TypeError('Pixel.add cannot receive null values');
          }
          return new OpenLayers.Pixel(this.x + x, this.y + y);
      }
docs: APIMethod: add
  
  Parameters:
  x - {Integer}
  y - {Integer}
  
  Returns:
  {<OpenLayers.Pixel>} A new Pixel with this pixel's x&y augmented by the
  values passed in.