Rewrite saving in terms of creating nodes.
Extracted out search by identity.
More movement of node knowledge into a single location.
Moved node updating down into nodes.
There was already a way to connect nodes.
Don't operate on nodes, operate on objects.
Consistent treatment of nodes and the beginning of an explicit graph.
Better formatting.
Moving towards an explicit graph.
Renaming raw graph traversal functions.
Centralising the description and use of the domain graph.