JointJS embedded links

HTML

<link rel="stylesheet" href="http://www.jointjs.com/downloads/joint.css">
<script src="http://www.jointjs.com/downloads/joint.js"></script>
<div id="easel"></div>
<button id="button">embed links</button><br/>
Drag Parent before and after embedding links into Parent using above button

JavaScript

var graph = new joint.dia.Graph;
var paper = new joint.dia.Paper({
    el: $('#easel'),
    width: 600,
    height: 200,
    gridSize: 1,
    model: graph
});
var parent = new joint.shapes.basic.Rect({
    position: {x: 100,y: 30},
    size: {width: 100,height: 30},
    attrs: {rect: {fill: 'blue'},
            text: {text: 'parent',fill: 'white'}}
});
var child = new joint.shapes.basic.Rect({
    position: {x: 70,y: 130},
    size: {width: 70,height: 30},
    attrs: {rect: {fill: 'lightgreen',rx: 5,ry: 5},
            text: {text: 'child',fill: 'white'}}
});	
link = new joint.dia.Link({
    source: {id:parent.id},
    target: {id:child.id}})
parent.embed(child);
var child2 = child.clone().translate(100);
var link2 = new joint.dia.Link({
    source: {id: parent.id},
    target: {id: child2.id},
    vertices: [{x: 210,y: 75}, {x: 190,y: 105}]
});
parent.embed(child2);

$("#button").click(function () {
    switch ($("#button").text().split(' ')[0]) {
        case 'embed':
            parent.embed(link);
            parent.embed(link2);
            $("#button").text('unembed links');
            break;
        case 'unembed':
            parent.unembed(link);
            parent.unembed(link2);
            $("#button").text('embed links');
    };
});
graph.addCells([parent, child, child2, link, link2]);