public void step(SimState state) {
    diffusers.step(state);

    // copy HexaBugs.this.valgrid2 to HexaBugs.this.valgrid
    HexaBugs hexabugs = (HexaBugs) state;
    hexabugs.valgrid.setTo(hexabugs.valgrid2);
  }
 /**
  * We'll have Hexabugs call this in its stop() method to give US a chance to call cleanup on our
  * underlying ParallelSequence so we don't leak threads.
  */
 public void cleanup() {
   diffusers.cleanup();
 }