code: function(controls) {
          if (!(OpenLayers.Util.isArray(controls))) {
              controls = [controls];
          }
          this.controls = this.controls.concat(controls);
  
          for (var i=0, len=controls.length; i<len; i++) {
              var control = controls[i],
                  element = this.createControlMarkup(control);
              OpenLayers.Element.addClass(element, 
                                          control.displayClass + "ItemInactive");
              OpenLayers.Element.addClass(element, "olButton");
              if (control.title != ""  && !element.title) {
                  element.title = control.title;
              }
              control.panel_div = element;
          }
  
          if (this.map) { // map.addControl() has already been called on the panel
              this.addControlsToMap(controls);
              this.redraw();
          }
      }
docs: APIMethod: addControls
  To build a toolbar, you add a set of controls to it. addControls
  lets you add a single control or a list of controls to the
  Control Panel.
  
  Parameters:
  controls - {<OpenLayers.Control>} Controls to add in the panel.