instruct

Tells vehicle what to do about the next stop it asks about.

The "be told" direction of stop control: a controller that has decided this vehicle is running late leaves a Skip here, and the vehicle collects it when its ksl.modeling.fleet.policies.DispatcherStopControl next asks. Nothing happens until it does, which is deliberate -- a vehicle mid-leg is somewhere, and an instruction that took effect between stops would be an instruction about nothing.

Has no effect on a vehicle whose control does not consult the dispatcher.