1. What technique can we use to implement the abstract factory pattern?
2. How do we prevent a singleton from being initialized multiple times in a multithreaded application?
3. What Julia feature is essential to implementing the observer pattern?
4. How can we customize an operation using the template method pattern?
5. How do we make an adapter to implement a target interface?
6. What is the benefit of the flyweight pattern and what strategy can we use to achieve it?
7. What Julia feature can we use to implement the strategy pattern?