C# arbitrary type to dictionary

Program.cs

using System;
using System.Collections.Generic;
using System.Linq.Expressions;

public class Foo
{
	public string BarBar { get; set; }
	public int BazBazBaz { get; set; }
}

public class Program
{
	public static void Main()
	{
		var foo = new Foo
		{
			BarBar = "Hello",
			BazBazBaz = 12345
		}.Convert();
		
		foreach (var (key, value) in foo)
		{
			Console.WriteLine("{0} {1}", key, value);	
		}
	}
}

public static class FormDataConverterExtensions
{
	public static Dictionary<string, string> Convert<T>(this T arg)
	{
		return FormDataConverter<T>.Convert(arg);
	}
		
}

public static class FormDataConverter<T>
{
    public static Func<T, Dictionary<string, string>> Convert { get; private set; }
    static FormDataConverter()
    {
        var sourceType = typeof(T);
        var sourceParam = Expression.Parameter(sourceType);
        var sourceTypeProperties = sourceType.GetProperties();
        List<ElementInit> elementInits = new(sourceTypeProperties.Length);

        var dictionaryType = typeof(Dictionary<string, string>);
        var dictionaryNew = Expression.New(dictionaryType);
        var addMethod = dictionaryType.GetMethod("Add");

        var stringType = typeof(string);

        foreach (var sourceProperty in sourceTypeProperties)
        {
            var sourceGetMethod = sourceProperty.GetGetMethod();
            if (sourceGetMethod is null)
                continue;

            var key = Expression.Constant(sourceProperty.Name);
            var value = Expression.Call(sourceParam, sourceGetMethod);
            var valueType = value.Type;
            if (!valueType.Equals(stringType))
            {
                var valueToString = value.Type.GetMethod("ToString", Array.Empty<Type>());
                value = Expression.Call(value, valueToString);
            }
			
            elementInits.Add(Expression.ElementInit(addMethod, key, value));
        }

        Convert = Expression.Lambda<Func<T, Dictionary<string, string>>>(
            Expression.ListInit(dictionaryNew, elementInits),
			sourceParam
        ).Compile();
    }
}