docs: def action_verify_checksum(self, ids):
          """Inactivate users."""
          try:
              count = 0
              for file_id in ids:
                  f = FileInstance.query.filter_by(
                      id=uuid.UUID(file_id)).one_or_none()
                  if f is None:
                      raise ValueError(_("Cannot find file instance."))
                  verify_checksum.delay(file_id)
                  count += 1
              if count > 0:
                  flash(_('Fixity check(s) sent to queue.'), 'success')
          except Exception as exc:
              if not self.handle_view_exception(exc):
                  raise
              current_app.logger.exception(str(exc))  # pragma: no cover
              flash(_('Failed to run fixity checks.'),
                    'error')