code: function Strategy(options, verify) {
  
    if (typeof options == 'function') {
      verify = options;
      options = {};
    }
    if (!verify) {
      throw new Error('cas authentication strategy requires a verify function');
    }
  
    this.ssoBase = options.ssoBaseURL;
    this.serverBaseURL = options.serverBaseURL;
    this.parsed = url.parse(this.ssoBase);
    if (this.parsed.protocol === 'http:') {
      this.client = http;
    } else {
      this.client = https;
    }
  
    passport.Strategy.call(this);
  
    this.name = 'cas';
    this._verify = verify;
  }
docs: Creates an instance of `Strategy`.