@Override
/** completes the abstract CacheLoader superclass */
public Tile load(TileRequest req) throws Exception {
LOG.debug("tile cache miss; cache size is {}", this.tileCache.size());
return new TemplateTile(req, graphService);
//return new TemplateTile(req, hashSampler);
//return new DynamicTile(req, hashSampler);
//return new DynamicTile(req, sampleFactory);
}