Bruce

An alternative (which would be useful) would be to have a `hash_tree`-like method that just returned the primary key IDs of the records in the tree, not the full records....

Turns out this is because in the `Capability` class I added: `default_scope -> { order( 'sort_order' ) }` Without this `self_and_ancestors` returns the ancestors in appropriate generation order. However without...

The issue appears to be that calling `node.namespaces` (which looks for namespaces on this node, and all the way up the document hierarchy) is hugely expensive within nokogiri, rather than...