private async Task <List <Models.Customer> > GetAllCustomers() { var collectionUri = _documentDbHelper.CreateSourceCustomerDocumentCollectionUri(); var client = _databaseClient.CreateSourceDocumentClient(); if (client == null) { return(null); } var queryCust = client.CreateDocumentQuery <Models.Customer>(collectionUri).AsDocumentQuery(); var customers = new List <Models.Customer>(); while (queryCust.HasMoreResults) { var response = await queryCust.ExecuteNextAsync <Models.Customer>(); customers.AddRange(response); } return(customers.Any() ? customers : null); }