code: private void purge()
    {
      if (TraceComponent.isAnyTracingEnabled() && _tc.isEntryEnabled()) SibTr.entry(this, _tc, "purge");
  
      Iterator<Map.Entry<K,TimedValue<V>>> it = _realMap.entrySet().iterator();
      while (it.hasNext())
      {
        Map.Entry<K,TimedValue<V>> entry = it.next();
        TimedValue<V> value = entry.getValue();
        if (value.hasExipred())
        {
          it.remove();
          if (TraceComponent.isAnyTracingEnabled() && _tc.isDebugEnabled())
          {
            SibTr.debug(_tc, "The value with the key " + entry.getKey() + " has expired");
          }
        }
      }
      
      if (TraceComponent.isAnyTracingEnabled() && _tc.isEntryEnabled()) SibTr.exit(this, _tc, "purge");
    }
docs: This method removes any expired data from the map.