using System;

public class Test
{
	private static DeviredExample _devired;
	public static void Main()
	{
		_devired = new DeviredExample();
		_devired.CallMethod += (sender, message) =>
        {
			Console.WriteLine(message);
        };
        _devired.SayHello();
	}
}

    public class Example
    {
        public void SayHello() => Console.WriteLine("Hello");
    }

    public class DeviredExample : Example
    {
        public delegate void MethodCall(object sender, string message);

        public event MethodCall CallMethod;
        protected virtual void OnCallMethod(string message, Action callback)
        {
            callback?.Invoke();
            CallMethod?.Invoke(this, message);
        }

        public new void SayHello()
        {
            OnCallMethod("Say hello called", () => base.SayHello());
        }
    }