Ms. Weir was engaged by Canada Post to deliver advertising flyers for a five-year term. She was entitled to payment on a per-piece basis. The contract provided that Canada Post could terminate the agreement on 60 days' notice if it changed its ad flyer distribution system and "alternatively, Canada Post may in its sole discretion terminate this agreement immediately on giving written notice to the Contractor." Payment per piece became costly for Canada Post, and two years later it instituted a new payment system based on packages (containing several pieces). Is Canada Post entitled to terminate the contract with Ms. Weir? What evidence is the relevant? Is it a contract at all when one party has so much discretion?