code: function accumulateDirectDispatchesSingle(event) {
    if (event && event.dispatchConfig.registrationName) {
      accumulateDispatches(event._targetInst, null, event);
    }
  }
docs: Accumulates dispatches on an `SyntheticEvent`, but only for the
  `dispatchMarker`.
  @param {SyntheticEvent} event