code: def group(self, *args):
          
          if len(args) == 0:
              args = (0,)
          grouplist = []
          for group in args:
              grouplist.append(self._get_slice(self._get_index(group), None))
          if len(grouplist) == 1:
              return grouplist[0]
          else:
              return tuple(grouplist)
docs: Returns one or more subgroups of the match. Each argument is either a
          group index or a group name.