[Twisted-Python] Woven, using microdom.lmx, and trying to use style sheets

[Hegedus, Matthew S]

If I may I'd like to request that future doc updates include more info on
microdom.lmx.

Is there a special way to have lmx generate xhtml with a specific style
class?

More specifically, if I have...

     <style type="text/css">
         tr.mySpecialTableRowStyleClass {color: white; background-color:
black}
     </style>

...in a xhtml template header, then how would I let a 'tr' lmx node know
that I want my custom style?

I tried t.tr['class'] = "mySpecialTableRowStyleClass" but then I got bitched
at with an "object does not support item assignment". Thanks,

Matthew