private void setSlot(int index, Unit unit, String message) {
// System.out.println("\nsetting slot at " + message + " index " + index + " to " + unit);
if (unit == null) {
return;
}
slots.set(index, unit);
// need to account for implicitly deleted last unit
makeConsistent();
// System.out.println("part after setting slot: " + this);
}
