code: function addRectGuides($canvas, parent) {
  	var guideProps, guide;
  	guideProps = $.extend({}, parent.guide, {
  		layer: true,
  		draggable: false,
  		type: 'rectangle',
  		handle: null
  	});
  	$canvas.addLayer(guideProps);
  	guide = $canvas.getLayer(-1);
  	parent._guide = guide;
  	$canvas.moveLayer(guide, -parent._handles.length - 1);
  	updateRectGuides(parent);
  }
docs: Add handle guides to rectangular layer