code: public synchronized Object getCacheKey(EvictionTableEntry evt) //3821 NK begin
      throws IOException,
                      EOFException,
                      FileManagerException,
                      ClassNotFoundException,
                      HashtableOnDiskException {
          Object key = null;
          if (filemgr == null) {
              throw new HashtableOnDiskException("No Filemanager");
          }
  
          HashtableEntry e = findEntry(evt, RETRIEVE_KEY);
          //TODO: Do we need to increment read_hits and read_requests
          if (e != null)
              key = e.getKey();
          return key;
      }
docs: This method is used by garbage collector to get the cache key for the corresponding EvictionTableEntry