     /**
       * If true, the element will not produce a ripple effect when interacted
       * with via the pointer.
       */
      noink: {
        type: Boolean,
        observer: '_noinkChanged'
      },

      /**
       * @type {Element|undefined}
       */
      _rippleContainer: {
        type: Object,
      }
    },

    /**
     * Ensures a `<paper-ripple>` element is available when the element is
     * focused.
     */
    _buttonStateChanged: function() {
      if (this.focused) {
        thi