.transform function retired?

I am trying to do a simple chart transform following the setTimeout example at:
http://c3js.org/samples/transform_bar.html

``` javascript
setTimeout(function () {
chart.transform('bar');
}, 1000);
```

but I am getting:
Uncaught TypeError: chart.transform is not a function

Has the syntax changed? i am using d3 ver 3.4.11 and c3 ver 0.1.29

Thank you.