emitter.on(PrincipalsConstants.events.REQUEST_TO_JOIN_GROUP, (ctx, group, oldGroup, memberChangeInfo) => {
  const millis = Date.now();
  const actorResource = new ActivityModel.ActivitySeedResource('user', ctx.user().id, { user: ctx.user() });
  const objectResource = new ActivityModel.ActivitySeedResource('group', group.id, { group });
  ActivityAPI.postActivity(