workflow.txt

function buyTicket(string plate, uint numOfBlocks) {
	// set parking ticket as bought for selected plate for selected duration
	// implement some discount for longer duration
};

function changePrice(uint price, Area area) onlyOwner {
	//  only owner of a contract can change price per area (from Area enum)
};

function checkTicket(string plate) boolean {
	// check if parking ticket is still valid for selected plate
	// possible add another role (controllers)?
	// return true/false
};

function cancelTicket(string plate) {
	// only user that bought ticket can cancel it and claim unused funds
	// send unclaimed funds to user
};

function transferTicket(string oldPlate, string newPlate) {
	// only user that bought ticket for selected plate can transfer it to other plate
};

function withdraw() onlyOwner {
	// only owner of a contract can withdraw funds
};