code: function set(target, key, value) {
            var old = target[key];
            target[key] = value;
            instance.emit(GQLBase.EVENT_MODEL_PROP_CHANGE, {
              model: target,
              old: old,
              key: key,
              value: value
            });
          }
docs: Proxy set() handler. This is where the change events are fired from
  
  @method GQLBase~set
  @param {Object} target the `GQLBase` model object
  @param {string} key the property name
  @param {mixed} value the new property value