Serializer class for serializing and deserializing any dictionary to xml

serializer.cs

using System.Xml.Serialization;

namespace Program
{
    public static class DictSerializer<K, V> where K : notnull
    {
        public static void Serialize<T>(T data, string filename) where T : IDictionary<K, V>
        {
            Tuple<K, V> pair = new();
            pair.Keys = data.Keys.ToArray();
            pair.Values = data.Values.ToArray();

            using (TextWriter writer = new StreamWriter(filename))
            {
                XmlSerializer serializer = new(typeof(Tuple<K, V>));
                serializer.Serialize(writer, pair);
            }
        }

        public static Dictionary<K, V> Deserialize(string filename)
        {
            object? obj;

            using (TextReader reader = new StreamReader(filename))
            {
                XmlSerializer serializer = new(typeof(Tuple<K, V>));
                obj = serializer.Deserialize(reader);
            }

            if (obj == null)
                throw new Exception("error, couldn't deserialize file");
            Tuple<K, V> tuple = (Tuple<K, V>)obj;

            Dictionary<K, V> dict = new();
            for (int i = 0; i < tuple.Keys.Length; i++)
            {
                dict.Add(tuple.Keys[i], tuple.Values[i]);
            }
            return dict;
        }
    }

    [Serializable]
    public class Tuple<K, V>
    {
        [XmlArrayItem(ElementName = "Key")]
        public K[] Keys;
        [XmlArrayItem(ElementName = "Value")]
        public V[] Values;

        public Tuple()
        {

        }
    }
}

usage:

Dictionary<ulong, string> mydict = new();
mydict[1234] = "hello world!";

DictSerializer<ulong, string>.Serialize(mydict, "testfile.txt");

DictSerializer<ulong, string>.Deserialize("testfile.txt);