code: def _management_form(self):
          
          if self.is_bound:
              form = ConcurrentManagementForm(self.data, auto_id=self.auto_id,
                                              prefix=self.prefix)
              if not form.is_valid():
                  raise ValidationError('ManagementForm data is missing or has been tampered with')
          else:
              form = ConcurrentManagementForm(auto_id=self.auto_id,
                                              prefix=self.prefix,
                                              initial={TOTAL_FORM_COUNT: self.total_form_count(),
                                                       INITIAL_FORM_COUNT: self.initial_form_count(),
                                                       MAX_NUM_FORM_COUNT: self.max_num},
                                              versions=[(form.instance.pk, get_revision_of_object(form.instance)) for form
                                                        in self.initial_forms])
          return form
docs: Returns the ManagementForm instance for this FormSet.