Design a class named StopWatch. The class contains:
■ The private data fields startTime and endTime with get methods.
■ A constructor that initializes startTime with the current time.
■ A method named start() that resets the startTime to the current time.
■ A method named stop() that sets the endTime to the current time.
■ A method named getElapsedTime() that returns the elapsed time for the stop watch in milliseconds.
Draw the UML diagram for the class, and then implement the class. Write a test program that measures the execution time of adding numbers from 1 to 1,000,000.