docs: function (direction) {
                  if (!this._cfg || !this._cfg.bind || !this._cfg.bind.value) {
                      // no binding for the value : return
                      return;
                  }
                  var currentBinding = this._cfg.bind.value;
                  var index = ariaUtilsArray.indexOf(this._instances, this), radioButtonNb = this._instances.length;
                  var bindings, next, nextBinding;
                  var waiAria = this._cfg.waiAria;
                  while (index >= 0 && index < radioButtonNb) {
                      index = index + direction;
                      if (waiAria) {
                          if (index < 0) {
                              index = radioButtonNb - 1;
                          } else if (index >= radioButtonNb) {
                              index = 0;
                          }
  
                      } else if (index < 0 || index >= radioButtonNb) {
                          break;
                      }
                      next = this._instances[index];
                      bindings = next._cfg.bind;
                      if (!next.getProperty("disabled") && bindings) {
                          nextBinding = bindings.value;
                          if (nextBinding) {
                              // next radio button needs to be bound to the same data. Otherwise, continue.
                              if (currentBinding.inside === nextBinding.inside && currentBinding.to === nextBinding.to) {
                                  next._setRadioValue();
                                  next._focus();
                                  break;
                              }
                          }
                      }
                  }
              }