public static Session createSession(String sessionToken) throws UnauthorizedException {
   SecurityInformation securityInformation = hah.getSecurityInformation(sessionToken);
   String emailAddress = securityInformation.getEmailAddress();
   User user = userservice.getByEmail(emailAddress);
   if (user == null) {
     throw new UnauthorizedException(
         "The email address given by the securityservice ("
             + emailAddress
             + ") is not registered to a user in elaborate");
   }
   return new Session(user.getId());
 }