private async Task <List <Models.ContactDetails> > GetAllContacts() { var collectionUri = _documentDbHelper.CreateSourceContactDocumentCollectionUri(); var client = _databaseClient.CreateSourceDocumentClient(); if (client == null) { return(null); } var queryCont = client.CreateDocumentQuery <Models.ContactDetails>(collectionUri).AsDocumentQuery(); var contacts = new List <Models.ContactDetails>(); while (queryCont.HasMoreResults) { var response = await queryCont.ExecuteNextAsync <Models.ContactDetails>(); contacts.AddRange(response); } return(contacts.Any() ? contacts : null); }