_modifyValue(increase) {
      let selectedValue = this.selectedValue;
      const replacementValue = this.lastItemReplacement;
      const minValue = this.itemMin;
      const maxValue = this.itemMax * (this.showInnerCircle ? 2 : 1);
      let step = this.valueStep;
      let newValue;
      // fix step in order to change value to the nearest possible if step is > 1
      if (selectedValue % step !== 0) {
        newValue = increase ? Math.ceil(selectedValue / step) * step : Math.floor(selectedValue / step) * step;
        step = Math.abs(selectedValue - newValue);
      }
      if (selectedValue === replacementValue) {
        selectedValue = maxValue;
      }
      if (increase) {
        selectedValue += step;
        if (selectedValue > maxValue) {
          selectedValue -= maxValue;
        }
      } else {
        selectedValue -= step;
        if (selectedValue < minValue) {
          selectedValue = maxValue;
        }
      }
      this._setSelectedValue(selectedValue);
    }
Mousewheel handler. Increases/decreases value of the clock.

@param {boolean} increase whether to increase or decrease the value