@Override void sameOwnerCheck() {
		int index = 0;
		PurchasableCircularList next = nextGroupElement;
		while(!next.equals(this)) {
			if(next.getOwner() != null && next.getOwner().equals(getOwner())) {
				index++;
				if(index == INCOME.length - 1) {
					break;
				}
			}
			next = next.getNextGroupElement();
		}
		next = this;
		do {
			if(next.getOwner() != null && next.getOwner().equals(getOwner())) {
				next.setStage(index);
			}
			next = next.getNextGroupElement();
		} while(!next.equals(this));
		firePurchasableEvent();
	}