[basex-talk] Add namespace bindings via copy/modify/return

[Hans-Juergen Rennau via BaseX-Talk]

Dear BaseX people,
I cannot use copy/modify/return in order to add a namespacing:
let $doc := <doc><a/></doc>return    copy $doc_ := $doc    modify      insert 
node namespace xyz {'https://basex.org/ns'} into $doc_    return $doc_
=><doc>  <a/></doc>
Is this a bug?
Kind regards,Hans-Jürgen