TODO: return the list of models involved in a deadlock.
Note that Many execution errors are not implemented at all at the
moment and will need separate PRs, namely:
- Terminated
- ModelError
- Panic
The `schedule_*event_in` and `schedule_*event_at` pairs of methods are
each merged into a single overloaded method accepting either a relative
`Duration`or an absolute `MonotonicTime`.
