`spiff-element-units` decomposes workflows into `element units` that can be executed in isolation. This allows for incrementally executing large workflows.
1. A full workflow is loaded into `SpiffWorkflow` once to find all the specs. There have been recent changes to `SpiffWorkflow` that support loading single files. Once tested this assumption will be removed.
1. Callers can support lazy loading of subprocess specs. Please see `helpers.py` under `tests/integration` for an example. Once this stabilizes more documentation will be provided.
Returns the json representation of a workflow capable of executing the first element unit available in `process_id` for the `element_id` associated with `cache_key`. This can be used to start or resume a process from previously cached element units.