TzdbDateTimeZoneSource.FromStream is missing

[rodion-m]

Hello! The method TzdbDateTimeZoneSource.FromStream doesn't exist in this repo at all, but it's using inside ToTzdbDateTimeZoneSource for example.

  TzdbDateTimeZoneSource ToTzdbDateTimeZoneSource() {
    var ms = new MemoryStream();
    var writer = new TzdbStreamWriter();
    writer.write(this,
        new WindowsZones("n/a", version, "n/a", <MapZone>[]), // No Windows mappings,
        new Map<String, String>(), // No additional name-to-id mappings
        BinaryWriter(ms));
    ms.position = 0;
    return TzdbDateTimeZoneSource.FromStream(ms); <<<<<<<<<<<<<<<<<<<<< is missing
  }

Please fix it.