text: /**
   * Central Authentication Service (CAS) Authentication Protocol
   *
   * CAS is a single sign-on protocol meant to give a user access to
   * more than one application by only submitting their credentials once.
   *
   * @param {Object}   req
   * @param {string}   identifier
   * @param {Function} next
   */
  module.exports = function (req, identifier, next) {
    const query    = {
      identifier: identifier,
      protocol: 'cas'
    };
  
    passport.connect(req, query, {username: identifier}, next);
  };
  