for (Unit subUnit : this.getSubUnits()) {
for (Unit subUnit : unit.getSubUnits()) {
    private void readAndSaveInactiveSubUnits(Unit unit, Set<Unit> allInactiveSubUnits, Date currentDate){        if (!unit.isActive(currentDate)) {            allInactiveSubUnits.add(unit);        }        for (Unit subUnit : this.getSubUnits()) {            readAndSaveInactiveSubUnits(subUnit, allInactiveSubUnits, currentDate);        }      }