docs: function (event) {
                  if (event.keyCode == aria.DomEvent.KC_SPACE) {
                      this._setRadioValue();
                      event.preventDefault(true);
                  } else if (event.keyCode == aria.DomEvent.KC_LEFT) {
                      this._navigate(-1);
                      event.preventDefault(true);
                  } else if (event.keyCode == aria.DomEvent.KC_RIGHT) {
                      this._navigate(+1);
                      event.preventDefault(true);
                  } else if (event.keyCode == aria.DomEvent.KC_DOWN) {
                      this._navigate(+1);
                      event.preventDefault(true);
                  } else if (event.keyCode == aria.DomEvent.KC_UP) {
                      this._navigate(-1);
                      event.preventDefault(true);
                  }
              }