MonoBehaviour's CancelRoutine() that doesn't just pause a routine like StopRoutine() does

CancellabeEnumeratorTest.cs

using System.Collections;
using UnityEngine;

//Now Debug.Log ("End printing") will be shown when you cancel the inner coroutine
public class CancellabeEnumeratorTest : MonoBehaviour {
	
	static int a = 0;
	IEnumerator printRoutine = null;
	
	void Start() {
		StartCoroutine (main ());
		StartCoroutine (endPrinterAfter (4.0f));
	}
	
	IEnumerator endPrinterAfter(float seconds) {
		yield return new WaitForSeconds (seconds);
		this.CancelRoutine (printRoutine);
	}
	
	IEnumerator main() {
		Debug.Log ("Begin printing");
		printRoutine = printer ().Cancellable();
		yield return StartCoroutine (printRoutine);
		Debug.Log ("End printing");
	}
	
	IEnumerator printer() {
		while (true) {
			Debug.Log("Printing "+(a++)); 
			yield return new WaitForSeconds(0.5f);
		}
	}
}

CancellableEnumerator.cs

using UnityEngine;
using System.Collections;

public interface ICancellabeEnumerator : IEnumerator {
	void Cancel();
	bool IsCancelled();
}

class CancellableEnumerator : ICancellabeEnumerator {
	
	private IEnumerator _wrappedEnumerator;
	private bool _cancelled = false;
	
	public CancellableEnumerator(IEnumerator originalEnumerator) {
		_wrappedEnumerator = originalEnumerator;
	}
	
	public bool MoveNext()
	{
		return !_cancelled && _wrappedEnumerator.MoveNext ();
	}
	
	public object Current
	{
		get
		{
			return _wrappedEnumerator.Current;
		}
	}
	
	public void Reset()
	{
		_wrappedEnumerator.Reset ();
		_cancelled = false;
	}
	
	public void Reset(IEnumerator enumerator) {
		_cancelled = false;
		_wrappedEnumerator = enumerator;
	}
	
	public void Cancel() {
		_cancelled = true;
	}
	
	public bool IsCancelled() {
		return _cancelled;
	}
}

public static class ICancellableEnumeratorExtensions {

	public static ICancellabeEnumerator Cancellable(this IEnumerator enumerator) {
		return new CancellableEnumerator(enumerator);
	}

	public static bool Cancel(this IEnumerator enumerator,bool ignoreNull = false) {

		if (ignoreNull && enumerator == null)
			return false;

		ICancellabeEnumerator cancellableEnumerator = enumerator as ICancellabeEnumerator;

		if (cancellableEnumerator == null) {
			Debug.LogError ("Trying to cancel a non-cancellable enumerator. Make sure you are using a cancellable enumerator by calling Cancellable()");
			return false;
		} else {
			cancellableEnumerator.Cancel ();
			return true;
		}
	}
}

public static class MonoBehaviourCancelRoutineExtensions {

	public static bool CancelRoutine(this MonoBehaviour mono, IEnumerator enumerator, bool ignoreNull = false) {
		return enumerator.Cancel ();
	}
}