Could you please add (at least) a test for this variation?

```scala
scala> val foo = <foo xmlns="http://foo.com/"><bar xmlns="http://bar.com/"><baz/></bar></foo>
foo: scala.xml.Elem = <foo xmlns="http://foo.com/"><bar xmlns="http://bar.com/"><baz></baz></bar></foo>

scala> foo.child.head.scope.toString
res2: String = " xmlns="http://bar.com/" xmlns="http://foo.com/""
```