public async Task<IEnumerable<DeviceToken>> GetUserDeviceTokensAsync(IEnumerable<string> userIds)
{
var keys = new RedisKey[userIds.Count()];
for (int i = 0; i < userIds.Count(); i++)
{
keys[i] = userIds.ElementAt(i);
}
var dtJsons = await pubsubRedis.GetDatabase().StringGetAsync(keys.ToArray(), CommandFlags.PreferSlave);
return from item in dtJsons select JsonToDeviceToken(item);
}
