private void loadToCache(final String filename) {
final FileSystem fileSystem = vertx.fileSystem();
if (fileSystem.existsSync(filename)) {
FileProps fileProps = fileSystem.propsSync(filename);
final Date lastModified = fileProps.lastModifiedTime();
// load from the file system
Buffer content = fileSystem.readFileSync(filename);
// cache the result
cache.put(filename, new LRUCache.CacheEntry<String, T>(lastModified, content.toString(contentEncoding())));
}