title: Fullcalendar v5 remove all events on button click
body: <p>I want to remove all events in fullcalendar v5 upon click of a button, the code below works fine</p>
  
  <pre><code>calendar.addEventSource([
      {
        title: 'Business Lunch',
        start: '2020-04-03T01:00:00',
      },
  ]);
  </code></pre>
  
  <p>But how can I able to remove/clear/delete all events after button click?
  The older version of fullcalendar has this method</p>
  
  <pre><code>calendar.fullCalendar( 'removeEvents', []);
  </code></pre>
  
  <p>How about for v5? I tried the code below but it gives me an error <code>remove is not a function</code>. I even tried <code>calendar.refetchEvents();</code>but nothing works.</p>
  
  <pre><code>$('.button').click(function(event) {
      calendar.remove();
  });
  </code></pre>