Article: The OOP has been explained wrongly to you

WashingService.java

class WashingService {
    private static final BigDecimal MAX_LAUNDRY_WEIGHT = BigDecimal.valueOf(7);

    Collection<LaundryElement> washWool(WashingMachine washingMachine, 
                                        Collection<LaundryElement> laundry, 
                                        Integer spinSpeed, 
                                        Integer temperature) {
        List<LaundryElement> laundryToBeDone = maximumLoadFrom(laundry, WOOL);
        washingMachine.setLaundry(laundryToBeDone);
        if (spinSpeed >= 0 && spinSpeed <= 400) {
            washingMachine.setSpinSpeed(spinSpeed);
        } else {
            washingMachine.setSpinSpeed(400);
        }
        if (temperature >= 0 && temperature <= 40) {
            washingMachine.setTemperature(temperature);
        } else {
            washingMachine.setTemperature(40);
        }
        washingMachine.wash();
        return washingMachine.getLaundry();
    }
    
    Collection<LaundryElement> washCotton(WashingMachine washingMachine, Collection<LaundryElement> laundry, Integer spinSpeed, Integer temperature) {
        // similar implementation as in washWool
    }
    
    Collection<LaundryElement> washSilk(WashingMachine washingMachine, Collection<LaundryElement> laundry, Integer spinSpeed, Integer temperature) {
        // similar implementation as in washWool
    }

    private List<LaundryElement> maximumLoadFrom(Collection<LaundryElement> laundry, 
                                                 Fabric fabricType) {
        List<LaundryElement> laundryToBeDone = new ArrayList<>();
        laundry.stream()
               .filter(laundryElement -> laundryElement.getType().equals(fabricType))
               .forEach(nextLaundryElement -> {
                   if (canFitAnotherLaundry(laundryToBeDone, nextLaundryElement)) {
                       laundryToBeDone.add(nextLaundryElement);
                   }
               });
        return laundryToBeDone;
    }

    private boolean canFitAnotherLaundry(List<LaundryElement> laundryToBeDone, 
                                         LaundryElement nextLaundryElement) {
        return totalWeightOf(laundryToBeDone).add(nextLaundryElement.getWeight())
            .compareTo(MAX_LAUNDRY_WEIGHT) <= 0;
    }
}