public async Task <List <dynamic> > GetSessionsWithVenuePostCodeAsync()
        {
            var collectionUri = DocumentDBHelper.CreateSessionDocumentCollectionUri();

            var client = DocumentDBClient.CreateDocumentClient();

            var sessionsWithVenuePostcodesQuery = client
                                                  ?.CreateDocumentQuery <Session>(collectionUri, new FeedOptions {
                MaxItemCount = 1000
            })
                                                  .Where(x => x.VenuePostCode != null)
                                                  .AsDocumentQuery();

            if (sessionsWithVenuePostcodesQuery == null)
            {
                return(null);
            }

            var sessions = new List <dynamic>();

            while (sessionsWithVenuePostcodesQuery.HasMoreResults)
            {
                var response = await sessionsWithVenuePostcodesQuery.ExecuteNextAsync();

                sessions.AddRange(response);
            }

            return(sessions.Any() ? sessions : null);
        }