_modifyValue(modifier, fireChangeEvent = false) {
      let value;
      this.value = this._preciseValue(parseFloat(this.input.value));
      value = this.value + modifier;
      if (this.min !== undefined && value < this.min) {
        value = this.min;
      }
      if (this.max !== undefined && value > this.max) {
        value = this.max;
      }
      value = this._preciseValue(value);
      if (value !== this.value) {
        this.value = value;
        this._validate();
        this._setButtonState();
        this.focused = true;
        this.inputOuter.setAttribute("focused", "");
        if (fireChangeEvent) {
          this._fireChangeEvent();
        } else {
          this.input.focus();
        }
      }
    }
Value modifier - modifies the value of the component, validates the new value and enables/disables increment and
decrement buttons according to the value and min/max values (if set). Fires <code>change</code> event when requested

@param {Float} modifier modifies the value of the component with the given modifier (positive or negative)
@param {boolean} fireChangeEvent if <code>true</code>, fires <code>change</code> event when the value is changed