Note: Relates to narly bug in GetChildren CQ (Canned Query).
- when listing children by a specific node type, the list may still return all children rather than none (unless there is at least one instance of the type)
- when listing children by a specific node type, the list should only contain children of the given type
- if needed, force create at least one node of the given (super-) type
- can apply to in-built (eg. "cm") or custom types