TryReadElementFromXml method
Implementation
@override
Future<bool> TryReadElementFromXml(EwsServiceXmlReader reader) async {
  bool result = await super.TryReadElementFromXml(reader);
  if (!result) {
    if (reader.LocalName == XmlElementNames.Bitmask) {
      // EWS always returns the Bitmask value in hexadecimal
      this.bitmask = int.parse(
          reader.ReadAttributeValue(XmlAttributeNames.Value),
          radix: 16);
    }
  }
  return result;
}