code: def difference(self, other, sort=None):
          self._validate_sort_keyword(sort)
          self._assert_can_do_setop(other)
          other, result_names = self._convert_can_do_setop(other)
          if len(other) == 0:
              return self
          if self.equals(other):
              return MultiIndex(levels=self.levels,
                                codes=[[]] * self.nlevels,
                                names=result_names, verify_integrity=False)
          this = self._get_unique_index()
          indexer = this.get_indexer(other)
          indexer = indexer.take((indexer != -1).nonzero()[0])
          label_diff = np.setdiff1d(np.arange(this.size), indexer,
                                    assume_unique=True)
          difference = this.values.take(label_diff)
          if sort is None:
              difference = sorted(difference)
          if len(difference) == 0:
              return MultiIndex(levels=[[]] * self.nlevels,
                                codes=[[]] * self.nlevels,
                                names=result_names, verify_integrity=False)
          else:
              return MultiIndex.from_tuples(difference, sortorder=0,
                                            names=result_names)