code: def rollback(self, verbose=False):
          
          for ns, insts in self.instances.items():
              insts.reverse()
              for inst in insts:
                  try:
                      if verbose:
                          print(_format("Deleting instance {0}", inst.path))
                      self.conn.DeleteInstance(inst.path)
                  except CIMError as ce:
                      print(_format("Error deleting instance {0}", inst.path))
                      print(_format("     {0} {1}",
                                    ce.status_code, ce.status_description))
          for ns, cnames in self.class_names.items():
              self.default_namespace = ns
              cnames.reverse()
              for cname in cnames:
                  try:
                      if verbose:
                          print(_format("Deleting class {0!A}:{1!A}",
                                        ns, cname))
                      self.conn.DeleteClass(cname)
                  except CIMError as ce:
                      print(_format("Error deleting class {0!A}:{1!A}",
                                    ns, cname))
                      print(_format("     {0} {1}",
                                    ce.status_code, ce.status_description))
docs: Remove classes and instances from the underlying repository, that have
          been created in the local repository of this class.
  
          Limitation: At this point, only classes and instances will be removed,
          but not qualifiers.