title: node.js: how to use setInterval and clearInterval?
body: <p>This is my JS in nodeJS :</p>
  
  <pre><code>function test(a, room, seconds) {
      console.log(a, room, seconds);
  }
  
  intervalid = setInterval(test, 1000, 'room', 20);
  console.log('intervalid', intervalid);
  </code></pre>
  
  <p>Which returns me the output: </p>
  
  <pre><code>intervalid Timeout {
      _called: false,
      _idleTimeout: 1000,
      _idlePrev: TimersList {
          _idleNext: [Circular],
          _idlePrev: [Circular],
          _timer: Timer { '0': [Function: listOnTimeout], _list: [Circular] },
          _unrefed: false,
          msecs: 1000,
          nextTick: false
      },
      _idleNext: TimersList {
          _idleNext: [Circular],
          _idlePrev: [Circular],
          _timer: Timer { '0': [Function: listOnTimeout], _list: [Circular] },
          _unrefed: false,
          msecs: 1000,
          nextTick: false
      },
      _idleStart: 377,
      _onTimeout: [Function: test],
      _timerArgs: [ 'room', 20 ],
      _repeat: 1000
  }
  </code></pre>
  
  <p><strong>Whereas in simple Javascript it returns a simple INTEGER number</strong></p>
  
  <p>When I attach interval to an existing user object, example :</p>
  
  <pre><code>user.intervalid = setInterval(test, 1000, 'room', 20);
  </code></pre>
  
  <p>I am not able to clearInterval any more :</p>
  
  <pre><code>clearInterval(user.intervalid); // does not work
  </code></pre>