#region Serialization
        private static DataContractSerializer CreateSerializer()
        {
            var serializer = new DataContractSerializer(
                typeof(Player),
                new[] { typeof(Player) },
                int.MaxValue,
                true,
                true,
                null);

            return serializer;
        }
        private static DataContractSerializer CreateSerializer2()
        {
            var serializer = new DataContractSerializer(
                typeof(Player),
                new[] { typeof(Trainer) },
                int.MaxValue,
                true,
                true,
                null);

            return serializer;
        }
        private static DataContractSerializer CreateSerializer3()
        {
            var serializer = new DataContractSerializer(
                typeof(Player),
                new[] { typeof(FBase) },
                int.MaxValue,
                true,
                true,
                null);

            return serializer;
        }

        public void SaveTo(Stream stream)
        {
            var serializer = CreateSerializer();

            var xmlSettings = new XmlWriterSettings
            {
                CloseOutput = false,
                Indent = true,
                NewLineChars = Environment.NewLine,
            };

            using (var xmlWriter = XmlWriter.Create(stream, xmlSettings))
            {
                serializer.WriteObject(xmlWriter, this);
                xmlWriter.Flush();
            }
        }
        public void SaveTo2(Stream stream)
        {
            var serializer2 = CreateSerializer2();

            var xmlSettings = new XmlWriterSettings
            {
                CloseOutput = false,
                Indent = true,
                NewLineChars = Environment.NewLine,
            };

            using (var xmlWriter = XmlWriter.Create(stream, xmlSettings))
            {
                serializer2.WriteObject(xmlWriter, this);
                xmlWriter.Flush();
            }
        }
        public void SaveTo3(Stream stream)
        {
            var serializer3 = CreateSerializer3();

            var xmlSettings = new XmlWriterSettings
            {
                CloseOutput = false,
                Indent = true,
                NewLineChars = Environment.NewLine,
            };

            using (var xmlWriter = XmlWriter.Create(stream, xmlSettings))
            {
                serializer3.WriteObject(xmlWriter, this);
                xmlWriter.Flush();
            }
        }