connectedCallback() {
    super.connectedCallback();
    this.values = {
      max: this.max,
      min: this.min,
      step: this.step,
    };
    if (this._inputNode) {
      this._inputNode.role = 'spinbutton';
      this._inputNode.setAttribute('inputmode', 'decimal');
      this._inputNode.setAttribute('autocomplete', 'off');
    }
    this.addEventListener('keydown', this.__keyDownHandler);
    this.__setDefaultValidators();
    this.__toggleSpinnerButtonsState();
  }
The aria-valuetext attribute defines the human-readable text alternative of aria-valuenow.
@type {{[key: number]: string}}