code: function(source, dest) {
          // clear cached center location
          this.centerLonLat = null;
          var ll = OpenLayers.Projection.transform(
              {'x': this.left, 'y': this.bottom}, source, dest);
          var lr = OpenLayers.Projection.transform(
              {'x': this.right, 'y': this.bottom}, source, dest);
          var ul = OpenLayers.Projection.transform(
              {'x': this.left, 'y': this.top}, source, dest);
          var ur = OpenLayers.Projection.transform(
              {'x': this.right, 'y': this.top}, source, dest);
          this.left   = Math.min(ll.x, ul.x);
          this.bottom = Math.min(ll.y, lr.y);
          this.right  = Math.max(lr.x, ur.x);
          this.top    = Math.max(ul.y, ur.y);
          return this;
      }
docs: APIMethod: transform
  Transform the Bounds object from source to dest.
  
  Parameters:
  source - {<OpenLayers.Projection>} Source projection.
  dest   - {<OpenLayers.Projection>} Destination projection.
  
  Returns:
  {<OpenLayers.Bounds>} Itself, for use in chaining operations.