title: kineticjs - How to get points from a line
body: <p>If I create a line...</p>
  <pre><code> var line = new Kinetic.Line({
    points: [0 , 5, 0, 100],
    stroke: 'black',
    strokeWidth: 2,
    draggable: true
  </code></pre>
  <p>});</p>
  <p>And I attach a event...</p>
  <pre><code>   line.on(&quot;mouseup&quot;, function () {
        updateLineInput( this.attrs.points );
     });
  </code></pre>
  <p>How could I get the points back out? <code>this.attrs.points</code> does not work...</p>