code: function(control, callbacks, options) {
          OpenLayers.Handler.prototype.initialize.apply(this, arguments);
          // cache the bound event listener method so it can be unobserved later
          this.eventListener = OpenLayers.Function.bindAsEventListener(
              this.handleKeyEvent, this
          );
      }
docs: Constructor: OpenLayers.Handler.Keyboard
  Returns a new keyboard handler.
  
  Parameters:
  control - {<OpenLayers.Control>} The control that is making use of
  this handler.  If a handler is being used without a control, the
  handlers setMap method must be overridden to deal properly with
  the map.
  callbacks - {Object} An object containing a single function to be
  called when the drag operation is finished. The callback should
  expect to recieve a single argument, the pixel location of the event.
  Callbacks for 'keydown', 'keypress', and 'keyup' are supported.
  options - {Object} Optional object whose properties will be set on the
  handler.