Need of creating a refrence to hashmap

[amarlearning]

Can you help me in understanding the need of creating a new reference for hashmap slots named allSlots using the getter method? Considering we can use the class variable slots directly as this.slots.

lld-parking-lot/src/main/java/com/uditagarwal/model/ParkingLot.java

Lines 44 to 48 in 071f9a0

	final Map<Integer, Slot> allSlots = getSlots();
	if (!allSlots.containsKey(slotNumber)) {
	allSlots.put(slotNumber, new Slot(slotNumber));
	}
	return allSlots.get(slotNumber);