/** @param securityHandler The {@link SecurityHandler} to set on this context. */
  public void setSecurityHandler(SecurityHandler securityHandler) {
    if (isStarted()) throw new IllegalStateException("STARTED");

    Handler next = null;
    if (_securityHandler != null) {
      next = _securityHandler.getHandler();
      _securityHandler.setHandler(null);
      replaceHandler(_securityHandler, securityHandler);
    }

    _securityHandler = securityHandler;
    if (next != null && _securityHandler.getHandler() == null) _securityHandler.setHandler(next);
    relinkHandlers();
  }