Exercise 16 & 17 finished, Sixteen.java and ExerciseSixTeenBycle.java and SixteenCycleFactory.java and Cycle interface and CycleFactory interface explain factory pattern usage.
 * Interface:
 * Exercise 18: (2) Create a Cycle interface, with implementations Unicycle, Bicycle
and Tricycle. Create factories for each type of Cycle, and code that uses these factories.
 * Exercise 16: (1) Modify the solution to Exercise 18 from the Interfaces chapter to use
anonymous inner classes.
The usage is that: to create a factory or factory frameworks, you need two interfaces, one is a type interface, some methods defined in this interface, the other is factory interface, it only have one method that responsible to return a object of type interface. Implement them, you need implement the factory interface and return a object that implements type interface