Propose three design patterns that will improve your design from above desgin.For each design pattern suggestion, you need to explain the issue that the proposed pattern solves (for your design not in general) and how it solves this issue. You can show how the pattern is applied to your design using UML.

The requirements below partially describe a software that is aimed at providing an online dog minding service. The application allows booking a service with a dog minder, communication with the dog minder and real time tracking of dog walks (these requirements are omitted in this question). Draw a UML class diagram describing an object-oriented system using the list of requirements below. 1. The system has two types of users: owner and dog minder. 2. An owner has many dogs. 3. An owner has many addresses. 4. An owner can make a booking with a dog minder. 5. Each booking is for a dog, owner and dog miner. 6. An owner can have up to three bookings. 7. A dog minder can have many bookings. 8. Each booking is for a single service. 9. The system provides two types of services: dog walk and day care. 10. Each service has a description. 11. Each booking has a payment. 12. The system must allow unpaid bookings. 13. Each payment is made by an owner. 14. The system accepts two types of payments: paypal and (credit) card. 15. All users are kept in the system registry. HINTS: RQ2 and RQ3: The system must guarantee the removal of the dogs and addresses of an owner when the owner is removed from the system. RQ2 and RQ3: Does it makes sense to have an owner in the system without a dog or an address. RQ5: The system should allow dogs without booking. RQ8: The system assigns a separate service object to each booking (design decision). The same type of services has the exact same description. Please use the names below for the class names in your diagram: User, Owner, DogMinder, Address, Dog, Booking, Service, DogWalk, DayCare, Service Description, Payment, Paypal, Card, Registry