What does this program print after the same handler is added twice and removed once?
csharp
using System;
var signal = new Signal();
EventHandler handler = (_, _) => Console.WriteLine("called");
signal.Changed += handler;
signal.Changed += handler;
signal.Changed -= handler;
signal.Raise();
public sealed class Signal
{
public event EventHandler? Changed;
public void Raise() => Changed?.Invoke(this, EventArgs.Empty);
}