IssueTracker

At this moment GCacheEntry do not provides full implementation of
CacheEntry.

For instance,

   public long getCost() {
      throw new UnsupportedOperationException();
   }

   public long getCreationTime() {
      throw new UnsupportedOperationException();
   }

   public long getExpirationTime() {
      throw new UnsupportedOperationException();
   }

   public long getHits() {
      throw new UnsupportedOperationException();
   }

   public long getLastAccessTime() {
      throw new UnsupportedOperationException();
   }

   public long getLastUpdateTime() {
      throw new UnsupportedOperationException();
   }

   public long getVersion() {
      throw new UnsupportedOperationException();
   }

Please implement getVersion() at least.