code: function wrapmethods(sess) {
    var _save = sess.save;
  
    function save() {
      debug('saving %s', this.id);
      savedHash = hash(this);
      _save.apply(this, arguments);
    }
  
    Object.defineProperty(sess, 'save', {
      configurable: true,
      enumerable: false,
      value: save,
      writable: true
    });
  }
docs: wrap session methods