code: public boolean isUnauthenticated(Subject subject) {
          if (subject == null) {
              return true;
          }
  
          WSCredential wsCred = getWSCredential(subject);
          if (wsCred == null) {
              return true;
          } else {
              return wsCred.isUnauthenticated();
          }
      }
docs: Check whether the subject is un-authenticated or not.
  
  @param subject {@code null} is supported.
  @return Returns {@code true} if the Subject is either null
  or the UNAUTHENTICATED Subject. {@code false} otherwise.