public StickerContext(string id, string ownerId, TrelloAuthorization auth)
            : base(auth)
        {
            _ownerId = ownerId;
            Data.Id  = id;

            Previews = new ReadOnlyStickerPreviewCollection(this, auth);
        }
        public StickerContext(string id, string ownerId, TrelloAuthorization auth)
            : base(auth)
        {
            _ownerId = ownerId;
            Data.Id  = id;

            Previews            = new ReadOnlyStickerPreviewCollection(this, auth);
            Previews.Refreshed += (s, e) => OnMerged(new[] { nameof(Previews) });
        }