public async void Expireat()
{
var set = await DB.Set("mykey", "hello");
Write(set);
var extist = await DB.Exists("mykey");
Write(extist);
var expireat = await DB.Expireat("mykey", 1293840000);
Write(expireat);
extist = await DB.Exists("mykey");
Write(extist);
}