private Collection<ReferenceBean> getVictims() {
    Collection<ReferenceBean> victims = new LinkedList<ReferenceBean>();
    for (Iterator<ReferenceBean> rfit = treemap.iterator(); rfit.hasNext(); ) {
      ReferenceBean victim = rfit.next();
      if (!victim.isExpired()) break;

      victims.add(victim);
      rfit.remove();
    }
    return victims;
  }
  private void expire(Collection<ReferenceBean> victims) {
    if (0 == victims.size()) return;

    for (ReferenceBean victim : victims) extContainer.expire(victim.getKey());
  }