YamlDotNet - Serialize Private Properties

Question

By default YamlDotNet does not serialize private properties. Is it possible to serialize also private properties? In the end I would like to serialize all properties that do have the YamlMember Attribute.

using System;
using System.IO;
using YamlDotNet.Serialization;

class Foo
{
    public Foo() {}
    public Foo(int t1, int t2)
    {
        this.T1 = t1;
        this.T2 = t2;
    }

    [YamlMember(Alias = "t1")]
    private int T1 { get; set; }

    [YamlMember(Alias = "t2")]
    public int T2 { get; private set; }

    public void Print()
    {
        Console.WriteLine($"{this.T1} - {this.T2}");
    }
}


public class Program
{
    public static void Main()
    {
        var serializer = new SerializerBuilder().Build();
        var deserializer = new DeserializerBuilder().Build();
        var foo = new Foo(1, 2);

        var strWriter = new StringWriter();
        serializer.Serialize(strWriter, foo);
        // no t1 has been serialized

        Console.WriteLine(strWriter.ToString());

        var str = @"
t1: 3
t2: 4
";
        // Fails, "can't find t1"
        var foo2 = (Foo)deserializer.Deserialize(str, typeof(Foo));
        foo2.Print();
    }
}

I noticed there are some similar questions here on Stackoverflow, unfortunately without any answer, e.g. 1, 2, or this answer, that says it's easy to change but unfortunately not how.