Node.js Stylus Interpolation is not rendering the styles as show in docs

I'm trying to run a vendor specific css mixin with stylus and I took this straight from the docs, but It doesn't seem to be rendering the css at all. Any thoughts?

vendor(prop, args)
  -webkit-{prop} args
     -moz-{prop} args
      -ms-{prop} args
       -o-{prop} args
          {prop} args

border-radius()
  vendor('border-radius', arguments)

li
 border-radius 3px 3px 0 0

Should be working but when the stylesheet is rendered there's not border-radius property?

Also, doing just the mixin is working properly

border-radius()
  -webkit-border-radius arguments
  -moz-border-radius arguments
  -ms-border-radius arguments
  -o-border-radius arguments
  border-radius arguments

li
  border-radius 3px

Renders:

li{
  -webkit-border-radius: 3px
  -moz-border-radius: 3px
  -ms-border-radius: 3px
  -o-border-radius: 3px
  border-radius: 3px
}

As expected. Any thoughts on this?

Thanks

Hey I figured this out and thought I would post back the answer. What was tripping me up was that the mixin vendor(prop, args) were indented thus it was not rendering the code. Watch the indents!

vendor(prop, args)
  -webkit-{prop} args
     -moz-{prop} args
      -ms-{prop} args
       -o-{prop} args
          {prop} args

Should be:

vendor(prop, args)
  -webkit-{prop} args
  -moz-{prop} args
  -ms-{prop} args
  -o-{prop} args
  {prop} args