docs: function addonsManager_installAddon(aSpec) {
      var spec = aSpec || { };
      var addon = spec.addon;
      var timeout = spec.timeout;
      var button = "install";
      var waitFor = (spec.waitFor == undefined) ? true : spec.waitFor;
  
      var button = this.getAddonButton({addon: addon, button: button});
      this._controller.click(button);
  
      if (waitFor)
        this.waitForDownloaded({addon: addon, timeout: timeout});
    }