/**
   * Handle "SWAP" action
   *
   * @param req
   * @param rsp
   * @return true if a modification has resulted that requires persistance of the CoreContainer
   *     configuration.
   */
  protected boolean handleSwapAction(SolrQueryRequest req, SolrQueryResponse rsp) {
    final SolrParams params = req.getParams();
    final SolrParams required = params.required();

    final String cname = params.get(CoreAdminParams.CORE);
    boolean doPersist = params.getBool(CoreAdminParams.PERSISTENT, coreContainer.isPersistent());
    String other = required.get(CoreAdminParams.OTHER);
    coreContainer.swap(cname, other);
    return doPersist;
  }