Feature: EnsureNode #1
Description
node = Ensure(node, path) : resolve path, creating required nodes if they don't exist
exception on malforemd path, or when it requires creating somethignthat cannot be created.
argument binding should be supported
Operation might not be possible at the last node --> error
Is the Operation to ensure the node always unambigous?
[12345678] would have to create many nodes...
The node returned might not be a sub-node of the original node - right now, I'd ignore that; alternatively, ensure the node is part of the original node?