I have a simulation that I would like to re-implement in RepastS, but I’m not sure where to put what I’d refer to as environmental effects.  Simplified to its essence Events are inflected on a randomly chosen subset of Policyholder agents at each simulation time step.  In my original application the particular subset of Policyholders is selected, and the Events are generated, by the class that represents the simulation environment.  How would I implement this situation in RepastS?