public async Task TrackDeliveredAsync(IEnumerable <TrackingToken> tokens)
{
await userNotificationsStore.TrackDeliveredAsync(tokens);
foreach (var token in tokens.Where(x => x.IsValid && !string.IsNullOrWhiteSpace(x.Channel)))
{
var channel = channels.FirstOrDefault(x => x.Name == token.Channel);
if (channel != null)
{
await channel.HandleDeliveredAsync(token);
}
}
}
