code: def _bigger(interval1, interval2):
          
          if interval2.cardinality > interval1.cardinality:
              return interval2.copy()
          return interval1.copy()
docs: Return interval with bigger cardinality
          Refer Section 3.1
  
          :param interval1: first interval
          :param interval2: second interval
          :return: Interval or interval2 whichever has greater cardinality