* (125) Use the `null` divider by default for processes so that upon division, processes are generated by the composer, not a divider.
0.4.15
* (123) Extend `Composite.merge` to use steps and flows. * (124) Use `set` divider by default.
0.4.14
* (121) Fix a bug in `Store.divide()` where daughter cell states were by default the mother cell state. Instead, add support for an `initial_state` key in the `_divide` dictionary. * (122) Add an `_output` flag option to `Process.ports_schema`, which marks ports as output-only.
0.4.13
* Improve `topology_view` caching mechanism to speed up simulations that have a lot of division.
0.4.12
* Allow schema overrides to override step schemas.
0.4.11
* Assert that when `Engine` treats a process like a step, that process is actually a step. * Use `Process.is_step()` to check whether a process is a step instead of using `isinstance`.