[Twisted-Python] Can't check elements without uri in twisted.words.xish.domish.Element

[Goffi]

G'day,

in the method "elements" of twisted.words.xish.domish.Element, the 
function "generateElementsQNamed" is called event if the uri if None, so 
the uri is checked against None instead of not checked at all.

I think the function "generateElementsNamed" should be called instead, 
it looks like a bug for me.
Can you confirm ?

cheers
Goffi