docs: public Subject newSubject(final String identifier, final String confirmationMethod) {
          val confirmation = newSamlObject(SubjectConfirmation.class);
          val method = newSamlObject(ConfirmationMethod.class);
          method.setConfirmationMethod(confirmationMethod);
          confirmation.getConfirmationMethods().add(method);
          val nameIdentifier = newSamlObject(NameIdentifier.class);
          nameIdentifier.setValue(identifier);
          val subject = newSamlObject(Subject.class);
          subject.setNameIdentifier(nameIdentifier);
          subject.setSubjectConfirmation(confirmation);
          return subject;
      }