unregister(keyOrFactory) {
    const { _registry: registry } = this;
    const key =
      typeof keyOrFactory === 'function' ? keyFor(keyOrFactory) : keyOrFactory;

    registry.delete(key);
  }
Unregister a factory from the container via a key (e.g. `adapter:fetch`)
or Factory class.

@param {String|Function} keyOrFactory