Subject.cs

public class Subject<T> : IDisposable {
	Action<T> _action;
	bool _disposed;

	public void Subscribe(Action<T> a) {
		Asr.IsFalse(_disposed);
		_action += a;
	}

	public void Publish(T msg) {
		Asr.IsFalse(_disposed);
		_action.Invoke(msg);
	}

	public void Dispose() {
		Asr.IsFalse(_disposed);
		_disposed = true;
		_action = null;
	}
}