Declarative syntax - The *two* templates below should have IDENTICAL STRUCTURE
to this one. There are four cases to test:
1. Main document parsing (this chunk)
2. Template parsing (the template below with id=declarative)
3. Template/fragment cloning (a clone of the template with id=declarative)
4. Declarative Shadow DOM parsing (template with id=declarative_shadow_dom and shadowrootmode attribute)