handleImageLoaderEvent_(e) {
    switch (e.type) {
      case NetEventType.COMPLETE:
        this.completeCount += 1;

      case EventType.LOAD:
        this.loadCount += 1;
        this.imagesRemaining -= 1;
    }

    /** @suppress {visibility} suppression added to enable type checking */
    this.imageLoaderRemainingSize =
        googObject.getKeys(this.imageLoader_.imageIdToRequestMap_).length;

    if (this.imagesRemaining == 0) {
      this.imageLoader_.disposeInternal();
    }
  }
Disposes the image loader when handling the final image, prior to
dispatching the COMPLETE event. This allows verification that the state of
the ImageLoader is clean before the original event is dispatched to any
clients.
@private