code: function (user, password, sendImmediately) {
          $this.options.auth = (is(user).a(Object)) ? user : {
            user: user,
            password: password,
            sendImmediately: sendImmediately
          }
  
          return $this
        }
docs: Basic Header Authentication Method
  
  Supports user being an Object to reflect Request
  Supports user, password to reflect SuperAgent
  
  @param  {String|Object} user
  @param  {String} password
  @param  {Boolean} sendImmediately
  @return {Object}