Calendar calendar = this.calendarAggregate();
CalendarSharer sharerZoe = new CalendarSharer(
new Participant("zoe", "Zoe Doe", "zoe@saasovation.com"));
calendar.shareCalendarWith(sharerZoe);
CalendarSharer sharerJoe = new CalendarSharer(
new Participant("joe", "Joe Smith", "joe@saasovation.com"));
calendar.shareCalendarWith(sharerJoe);