public static async Task DeserializeString(string s, string encoding)
{
var enc = Encoding.GetEncoding(encoding);
var stream = new MemoryStream();
var streamWriter = new StreamWriter(stream, enc);
await streamWriter.WriteAsync(s);
await streamWriter.FlushAsync();
var settings = SmppSerializationSettings.Default;
settings.DefaultEncoding = enc;
var serializer = new SmppSerializer();
var result = await serializer.DeserializeAsync <string>(new SmppReader(stream, true), settings);
Assert.Equal(s, result);
}