code: def collapse(self):
          
  
          if self.cardinality:
              r = None
              for si in self._si_set:
                  r = r._union(si) if r is not None else si
  
              return r
  
          else:
              # This is an empty StridedInterval...
              return StridedInterval.empty(self._bits)
docs: Collapse into a StridedInterval instance.
  
          :return: A new StridedInterval instance.