code: function () {
                      this._closeTooltip();
                      var firePreviewChange = true;
                      if (this._tentativeRating < 0 || this._tentativeRating >= this._maxRating) {
                          firePreviewChange = false;
                      }
  
                      if (this._tentativeRating !== -1) {
                          if (this._tentativeRating < this._maxRating) {
                              this._tentativeRating++;
                          }
                      } else {
                          if (this._userRating !== 0) {
                              if (this._userRating < this._maxRating) {
                                  this._tentativeRating = this._userRating + 1;
                              } else {
                                  this._tentativeRating = this._maxRating;
                              }
                          } else {
                              this._tentativeRating = 1;
                          }
                      }
                      this._showTentativeRating(firePreviewChange, "keyboard");
                  }
docs: increase tentative rating by one