<?xml version="1.0"?>
<!DOCTYPE window [
  <!ENTITY fooSet '
    <addOrRemove foo:foo="foo"/>
    <addOrRemove foo:foo="bar"/>
    <addOrRemove foo:bar="foo"/>
    <addOrRemove foo:bar="bar"/>
    <addOrRemove foo:foo="foo" foo:bar="bar"/>
    <addOrRemove foo2:foo="foo"/>
    <addOrRemove foo="foo"/>
    <addOrRemove foo="bar"/>
    <addOrRemove bar="bar" foo="foo"/>
'>
]>
<window
  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
  xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
  xmlns:foo="foo"
  xmlns:foo2="foo"
  xmlns:bar="bar"
  >
  <vbox id="boxes">
    <groupbox id="master1" foo:foo="bar">
      &fooSet;
      <groupbox foo:foo="foo">
        &fooSet;
      </groupbox>
    </groupbox>
    <groupbox id="master2" foo:foo="foo">
      &fooSet;
      <groupbox foo:foo="bar">
        &fooSet;
      </groupbox>
    </groupbox>
    <groupbox id="master3">
      &fooSet;
      <groupbox foo2:foo="foo">
        &fooSet;
      </groupbox>
    </groupbox>
    <groupbox id="external">
      &fooSet;
    </groupbox>
  </vbox>
</window>
