code: function login (jar, token, username, password) {
    clearSession({jar: jar});
    var url = '//auth.roblox.com/v2/login';
    var post = {
      'ctype': 'Username',
      'cvalue': username,
      'password': password
    };
    var httpOpt = {
      url: url,
      options: {
        method: 'POST',
        json: post,
        resolveWithFullResponse: true,
        jar: jar,
        headers: {
          'X-CSRF-TOKEN': token
        }
      }
    };
    return http(httpOpt)
      .then(function (res) {
        var body = res.body;
        if (res.statusCode === 200) {
          if (body.twoStepVerificationData) {
            throw new Error('Two step verification is not supported');
          }
          if (settings.session_only) {
            var cookies = res.headers['set-cookie']; // If the user is already logged in a new cookie will not be returned.
            if (cookies) {
              var session = cookies.toString().match(/\.ROBLOSECURITY=(.*?);/)[1];
              jar.session = session;
            }
          }
          return body.user;
        } else {
          if (body.errors && body.errors.length > 0) {
            var errors = body.errors.map((e) => {
              return e.message;
            });
            throw new Error('Login failed: ' + errors.join(', '));
          }
        }
      });
  }
docs: Define