Contextmenu on the objects in fabricjs

Can you please help me in creating a context menu on the fabric object. I have googled a lot but couldn't find exact solution. I have created two objects as below on the fabric. How can i bind a context menu to the fabric object? Fiddle link: http://jsfiddle.net/fabricjs/S9sLu/

canvas.add(new fabric.Rect({ 
  left: 100, 
  top: 100, 
  width: 50, 
  height: 50, 
  fill: '#faa', 
  originX: 'left', 
  originY: 'top',
  centeredRotation: true
}));

canvas.add(new fabric.Circle({ 
  left: 300, 
  top: 300, 
  radius: 50, 
  fill: '#9f9', 
  originX: 'left', 
  originY: 'top',
  centeredRotation: true
}));

Thanks in advance.