especially the exploration stack is pushed down
first successful definition of all the JobPlanning classes
just the framework of classes necessary to pass the compiler;
all implementation is still stubbed
brainstorming how to implement the job planning stage
the idea is to built on top of the IterExplorer,
but have the "stack" of re-evaluation integrated
into a custom type, which exploits the static
node network structure to avoid heap allocations
solution idea: again use a builder function?
