private void integrityCheck() {
		PurchasableCircularList next = nextGroupElement;
		int stations = 0;
		int owned = 0;
		do {
			stations++;
			next = next.getNextGroupElement();
		} while(!next.equals(this));
		next = this;
		do {
			if(next.getOwner() != null && next.getOwner().equals(owner)) {
				owned++;
			}
			next = next.getNextGroupElement();
		} while(!next.equals(this));
		if(owned >= (stations * 0.75)) {
			stage = 3;
		} else if(owned >= (stations * 0.5)) {
			stage = 2;
		} else if(owned >= (stations * 0.25)) {
			stage = 1;
		} else {
			stage = 0;
		}
	}