[Unity] Pause and Resume coroutine

Test.cs

using UnityEngine;
using System.Collections;

public class Test : MonoBehaviour
{
    IEnumerator _routine;
    IEnumerator routine { get { return _routine ?? (_routine = RoutineImpl()); } }

    void OnEnable()
    {
        StartCoroutine(routine);
    }

    void OnDisable()
    {
        StopCoroutine(routine);
    }

    public IEnumerator RoutineImpl()
    {
        while (true)
        {
            Debug.LogFormat("[{0}] Log-A", Time.frameCount);
            yield return null;
            Debug.LogFormat("[{0}] Log-B", Time.frameCount);
            yield return null;
        }
    }
}