/// <exception cref="ArgumentException">Thrown when <paramref name="userId"/> is null or empty</exception>> public async Task <DeviceList> GetDevicesForUser(string userId, string clientId = null) { ArgumentGuard.NotNullOrEmpty(userId, nameof(userId)); var endpoint = QueryStringBuilder.Append($"/v1/users/{userId}/devices", "client_id", clientId); return(await TryRequest(() => _messageSender.Get <DeviceList>(endpoint))); }