Example of how graph classes can be turned into a more reusable pattern

As the roadmap includes 'using reusable charts as layouts', I thought I would provide a quick example of how a graph class can be rewritten to be split into two parts. A graph class that has no dependency on the raw domain space and that can be reused across a number of different projects. An adapter classes that accesses the graph class from within the (very specific) raw-app context.