i need a proper line to line code for the given program

Question II (Stopwatch) Design a class named StopWatch. The class contains: - Private data fields startTime and endTime with getter methods. A no-arg 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 stopwatch in milliseconds. Draw the UML diagram for the class then implement the class. Write a test program that measures the execution time of sorting 100,000 numbers using selection sort