Project: Duration Class
Write a mutable class to represent a time duration. Your class should represent time durations in the following units: ns, µs, ms, s, min, hour, day, week, month, year. Use an enumeration to represent the time duration units. You should have a default constructor that sets the internal value to 0. Write a setter that takes a value and an enumeration value for units. Include a getter that takes an enumeration value for units and returns the value in that measurement unit.