Task $20$: static keyword and Composition $($has$-$a$)$ relationship.

Aim:

static keyword to track the number of company objects created and distinguish between instance and static variables $($class variables$)$ and static methods $($class methods$).$

To implement the composition relationship between classes in java code, by using data fields, constructor and methods.

Title: Company and Department classes.

Summary: Understand a class that references one or more objects of other classes in instance variables. This allows you to model a has$-$a association between objects.

Question: In this task, Open OOPLab$9$Task$20$ project, then define class Company as the following UML class diagram.

Notice that: class Department is already defined.