`stopping-definition` to stop at a given bucket.

`stopping-definition` to stop at a given iteration.

`stopping-definition` to stop right now.

Stopping registry contains all `stopping-definition`.

![Entities](archi/simulation_engine/stopping_registry.png)

A reason why the `scheduler` stops. A `stopping-cause` contains:

* `context` data describing the context of the `stopping-criteria`, note its schema is defined freely by each `stopping-definition`.
* `current-event` the event that is about to be executed now. It could be null, if future-event is nil and no first event found.
* `stopping-criteria` telling the intent of the user to stop.

![Entities](archi/simulation_engine/stopping_cause.png)

Declares a `stopping-criteria` to instantiate `stopping-definition`s, it precises the `params` necessary for `stopping-evaluation`.
The data are:

* `model-end?` is set to `true` if the stopping-criteria is one possible end of the model. Note that more than one is possible for the same model. Note that these model `stopping-criteria` are not supposed to be linked with anything else than the business model itself (not the rendering, not the control/computation, ...)
* `params` is a map of parameters, which content is defined by the `stopping-definition`.
* `stopping-definition` is the `stopping-definition` as found in the `stopping-registry`.

![entities][archi/simulation_engine/stopping_stopping-criteria.png]

A `stopping-definition` defines what could cause the scheduler to stop.

* `doc` describes the definition.
* `id` name of the `stopping-definition`
* `next-possible?` tells if the next call of the `scheduler` will raise the same error.
* `stopping-evaluation` is the function to be called to evalute the criteria and decides if stops is true or not.

Note that only `stopping-definition` with `stopping-evaluation` properly set are callable by users. Others are built-in `stopping-definition` triggering `stopping-cause` in the `simulation-engine` bounded context.

![Entities](archi/simulation_engine/stopping_definition.png)