docs: function(control, callbacks, options) {
          OpenLayers.Handler.prototype.initialize.apply(this, arguments);
          this.dragHandler = new OpenLayers.Handler.Drag(
              this, 
              {
                  down: this.startBox, 
                  move: this.moveBox, 
                  out: this.removeBox,
                  up: this.endBox
              }, 
              {keyMask: this.keyMask}
          );
      }