/**
  * Sets the session tracking modes that are to become effective for this <tt>ServletContext</tt>.
  */
 @Override
 public void setSessionTrackingModes(Set<SessionTrackingMode> sessionTrackingModes) {
   if (SecurityUtil.isPackageProtectionEnabled()) {
     doPrivileged("setSessionTrackingModes", new Object[] {sessionTrackingModes});
   } else {
     context.setSessionTrackingModes(sessionTrackingModes);
   }
 }