Consider the following interface for an ADT for representing intervals (periods of time as opposed to instantaneous moments of time) typedef long Duration; // measured in seconds class DateTime ( public DateTime (int year, int month, int day, int hour, int minute, int second): /Il How many seconds between two times? Duration operator-(const Date Time& right) const class Interval public: Il // An interval is a period of time beginning with a starting time /I and running up to, but not including, its stop time Interval 0: Interval (DateTime start, DateTime stop); Interval (DateTime start, Duration length): DateTime getStart) const: void setStart (DateTime); DateTime getStop) const void setStop (Date Time): Duration getDuration: bool contains (DateTime d) bool overlaps (Interval intrvl); bool operator (const Interval& other) const; private: DateTime theStart, theStop; Using the JUnit style, write a self-checking test for the 3rd Interval constuctor