def _management_form(self):
        """Returns the ManagementForm instance for this FormSet."""
        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
Returns the ManagementForm instance for this FormSet.