destroy() {
    /** @type {!Array<!Promise>} */
    const destroys = [];
    for (const mechanism of this.mechanisms_.values()) {
      destroys.push(mechanism.destroy());
    }

    // Empty the map so that subsequent calls will be no-ops.
    this.mechanisms_.clear();

    return Promise.all(destroys);
  }
Free all resources used by the muxer, mechanisms, and cells. This should
not affect the stored content.

@override
@export