public MemberJoinEvent(WebhookEventSource source, long timestamp, string replyToken, IList <WebhookEventSource> members, string mode, string webhookEventId, DeliveryContext deliveryContext)
     : base(WebhookEventType.MemberJoined, source, timestamp, replyToken, mode, webhookEventId, deliveryContext)
 {
     Joined = new Moved(members);
 }
 public MemberLeaveEvent(WebhookEventSource source, long timestamp, IList <WebhookEventSource> members, string mode, string webhookEventId, DeliveryContext deliveryContext)
     : base(WebhookEventType.MemberLeft, source, timestamp, mode, webhookEventId, deliveryContext)
 {
     Left = new Moved(members);
 }