using System;

public class Program

{

    public static void Main()

    {

        "Hello World".CustomWrite(opt => {

            opt.Prefix = "My Text: ";

        });

    }

}

​

public static class ConsoleExtensions

{

    public static void CustomWrite(this string text, Action<WriteOpts> optUpdate)

    {

        var opts = new WriteOpts();

        optUpdate(opts);

        Console.WriteLine(opts.Prefix + text + opts.Suffix);

    }

    public class WriteOpts

    {

        public string Prefix { get; set; } = string.Empty;

        public string Suffix { get; set; } = string.Empty;

    }

}