/// <summary>
        /// Return a collection of thumbnails available for an item referenced by item-id
        /// </summary>
        /// <param name="itemReference"></param>
        /// <param name="thumbnailOptions"></param>
        /// <returns></returns>
        public async Task<ODThumbnailSet[]> GetThumbnailsForItemAsync(ODItemReference itemReference, ThumbnailRetrievalOptions thumbnailOptions)
        {
            if (!itemReference.IsValid())
                throw new ArgumentException("ItemReference was invalid. Requires either an ID or Path");

            var queryParams = ODataOptionsToQueryString(thumbnailOptions);
            Uri serviceUri = UriForItemReference(itemReference, ApiConstants.ThumbnailsRelationshipName, queryParams);
            var results = await DataModelForRequest<ODCollectionResponse<ODThumbnailSet>>(serviceUri, ApiConstants.HttpGet);

            if (null != results && results.Collection != null)
            {
                return results.Collection;
            }

            return null;
        }
        /// <summary>
        /// Return a collection of thumbnails available for an item referenced by item-id
        /// </summary>
        /// <param name="itemReference"></param>
        /// <param name="thumbnailOptions"></param>
        /// <returns></returns>
        public async Task <ODThumbnailSet[]> GetThumbnailsForItemAsync(ODItemReference itemReference, ThumbnailRetrievalOptions thumbnailOptions)
        {
            if (!itemReference.IsValid())
            {
                throw new ArgumentException("ItemReference was invalid. Requires either an ID or Path");
            }

            var queryParams = ODataOptionsToQueryString(thumbnailOptions);
            Uri serviceUri  = UriForItemReference(itemReference, ApiConstants.ThumbnailsRelationshipName, queryParams);
            var results     = await DataModelForRequest <ODCollectionResponse <ODThumbnailSet> >(serviceUri, ApiConstants.HttpGet);

            if (null != results && results.Collection != null)
            {
                return(results.Collection);
            }

            return(null);
        }