request
Ask for a decision at the current time, taken in an event of the element's own.
The epoch runs after the caller's event action completes, so the model is between events when the state is read and R2b's warrant is not required of the caller. Use it wherever a caller cannot vouch for the state it is calling from, or wherever nothing is waiting for the answer. It is also the repair for a lever write that wants a decision as a consequence of a decision: it is re-entrancy-safe by construction, because it only schedules.
The guarantee is real but weaker than a scheduled epoch's was: a zero-delay event lands at the current time later in the event order, not at the end of the instant, so events already queued at this time with lower ids still run first.
Throws
if the model is not running.