public CachedExternalResourceAdapter(
     String source,
     CachedExternalResource cached,
     ExternalResourceAccessor accessor,
     ExternalResourceMetaData metaData) {
   super(source, cached.getCachedFile(), metaData);
   this.cached = cached;
   this.accessor = accessor;
 }
 @Override
 public String toString() {
   return "CachedResource: " + cached.getCachedFile() + " for " + getName();
 }