Wrapping immutable value in a mutable box

WrappingImmutableValueInMutableBox.cs

using System;
using ImTools;
					
public class Program
{
	public static void Main()
	{
		var map = ImHashMap<string, string>.Empty;
		
		var map1 = map.AddOrUpdate("a", "42");	
		
		Console.WriteLine(map1.GetValueOrDefault("a"));
	}	
}

public static class Ext 
{
	public static void Add<K, V>(this Ref<ImHashMap<K, V>> map, K key, V value) 
	{
		map.Swap(m => m.AddOrUpdate(key, value));
	}
}

public static class FamiliarApi 
{
	public static void Example()
	{
		var map = Ref.Of(ImHashMap<string, string>.Empty);
		map.Add("b", "3.14");
		
		Console.WriteLine(map.Value.GetValueOrDefault("b"));
	}	
}