code: protected void updateSubjectWithTemporarySubjectContents() {
          subject.getPrincipals().addAll(temporarySubject.getPrincipals());
          subject.getPublicCredentials().addAll(temporarySubject.getPublicCredentials());
          subject.getPrivateCredentials().addAll(temporarySubject.getPrivateCredentials());
      }
docs: Sets the subject with the temporary subject contents that was not set already from the
  shared state.