title: How to deactivate all objects in Fabric.js
body: <p>How to deactivate all objects in Fabric.js before saving an image?</p>
  
  <pre><code>function rasterize() {
    if (!myscript.Canvas.supports('toDataURL')) {
      alert('This browser doesn\'t provide means to serialize canvas to an image');
    }
    else {
      /*i want to deactivate all object here*/
      window.open(canvas.toDataURL('png'));
    }
  }
  </code></pre>