code: function fireQueryParamDidChange(router, newState, queryParamChangelist) {
        // If queryParams changed trigger event
        if (queryParamChangelist) {
  
          // This is a little hacky but we need some way of storing
          // changed query params given that no activeTransition
          // is guaranteed to have occurred.
          router._changedQueryParams = queryParamChangelist.all;
          trigger(router, newState.handlerInfos, true, ['queryParamsDidChange', queryParamChangelist.changed, queryParamChangelist.all, queryParamChangelist.removed]);
          router._changedQueryParams = null;
        }
      }
docs: @private
  
  Fires queryParamsDidChange event