docs: def put_meta(request):
      """MNStorage.updateSystemMetadata(session, pid, sysmeta) → boolean.
  
      TODO: Currently, this call allows making breaking changes to SysMeta. We need to
      clarify what can be modified and what the behavior should be when working with SIDs
      and chains.
  
      """
      if django.conf.settings.REQUIRE_WHITELIST_FOR_UPDATE:
          d1_gmn.app.auth.assert_create_update_delete_permission(request)
      d1_gmn.app.util.coerce_put_post(request)
      d1_gmn.app.views.assert_db.post_has_mime_parts(
          request, (('field', 'pid'), ('file', 'sysmeta'))
      )
      pid = request.POST['pid']
      d1_gmn.app.auth.assert_allowed(request, d1_gmn.app.auth.WRITE_LEVEL, pid)
      new_sysmeta_pyxb = d1_gmn.app.sysmeta.deserialize(request.FILES['sysmeta'])
      d1_gmn.app.views.assert_sysmeta.has_matching_modified_timestamp(new_sysmeta_pyxb)
      d1_gmn.app.views.create.set_mn_controlled_values(
          request, new_sysmeta_pyxb, is_modification=True
      )
      d1_gmn.app.sysmeta.create_or_update(new_sysmeta_pyxb)
      d1_gmn.app.event_log.log_update_event(
          pid,
          request,
          timestamp=d1_common.date_time.normalize_datetime_to_utc(
              new_sysmeta_pyxb.dateUploaded
          ),
      )
      return d1_gmn.app.views.util.http_response_with_boolean_true_type()