private async Task OnSubjectChanged(MeetupSubjectChanged @event)
        {
            var meetupSuggest = new MeetupSuggest
            {
                MeetupId = @event.MeetupId,
                Subject  = @event.Subject,
                Suggest  = new CompletionField
                {
                    Input = new[] { @event.Subject }
                }
            };

            await _elasticClient.UpdateAsync <MeetupSuggest, object>(@event.MeetupId, (u) => u.Index(GetSuggestIndex()).Doc(meetupSuggest));
        }
        private async Task OnRegistered(MeetupRegistered @event)
        {
            var meetupSuggest = new MeetupSuggest
            {
                MeetupId = @event.MeetupId,
                Subject  = @event.Subject,
                Suggest  = new CompletionField
                {
                    Input = new[] { @event.Subject }
                }
            };

            await _elasticClient.IndexAsync <MeetupSuggest>(meetupSuggest, (u) => u.Index(GetSuggestIndex()).Id(meetupSuggest.MeetupId));
        }