title: element's "collapse" attribute not working?
body: <p>I'm trying to build a table as in this <a href="http://jsfiddle.net/6Texj/158/" rel="nofollow noreferrer">JSFiddle</a> which I found <a href="https://stackoverflow.com/questions/17544048/multi-level-tables-inside-another-if-clicked">here</a>.</p>
  
  <p>I notice lots of elements have a <code>collapse="&lt;boolean&gt;"</code> property and as long as the property is true, you will get a nice collapse animation. I tried finding documentation about the <code>collapse</code> attribute online as well and didn't find anything. However, I also noticed the version of angular is rather outdated (1.0.5 instead of 1.5 that I'm currently using). If I try to replace the reference to angular 1.5, the jsfiddle example also stops working. My question is, assuming collapse is deprecated, how can I reproduce this effect in angular 1.5?</p>