Another example
repeatSchedule=[Schedule createBegin: zone];
[repeatSchedule setRepeatInterval: 3];
repeatSchedule=[repeatSchedule createEnd];
[repeatSchedule at: 0 createActionTo: firm message:M(do)];
mainSchedule=[Schedule createBegin: zone];
[mainSchedule at:20 createActionTo: repeatSchedule
message: M(activateIn:):aSwarm];
[mainSchedule activateIn: aSwarm];
Purpose: A schedule which executes the “do” method on an
object called “firm” every 3 periods, starting at t=20