handleAvailableToken_(tile, token) {
    const tokenPool = this.getGlobalTokenPool_();

    // Exit early if the tile was aborted (e.g. because the layer was hidden or
    // this tile was panned out of view).
    if (tile.isDisposed() || tile.getStatus() == AbstractTile.Status.ABORTED) {
      tokenPool.releaseObject(token);
      return;
    }

    var key =
        events.listen(tile, AbstractTile.EventType.STATUS_CHANGED, function() {
          if (tile.isDone()) {
            events.unlistenByKey(key);
            tokenPool.releaseObject(token);
          }
        });

    tile.startLoad();
  }
Handles a request pool token being available by starting the tile load.
@param {AbstractTile} tile The tile to load.
@param {!Object} token The EE tile token pool object for this load.
@private