using System;

public class Program

{

    public static void Main()

    {

        var foo = new Foo();

        foo.Write();

        foo.Write();

    }

}

​

public class Foo

{

    public Guid Bar => Guid.NewGuid();

    public Guid Baz { get; }

    public Guid Bat { get; } = Guid.NewGuid();

    public Foo()

    {

        Baz = Guid.NewGuid();

    }

    public void Write()

    {

        Console.WriteLine($"Bar: {Bar}");

        Console.WriteLine($"Baz: {Baz}");

        Console.WriteLine($"Baz: {Bat}");

    }

}