docs: def is_valid_sid_for_new_standalone(sysmeta_pyxb):
      """Assert that any SID in ``sysmeta_pyxb`` can be assigned to a new standalone
      object."""
      sid = d1_common.xml.get_opt_val(sysmeta_pyxb, 'seriesId')
      if not d1_gmn.app.did.is_valid_sid_for_new_standalone(sid):
          raise d1_common.types.exceptions.IdentifierNotUnique(
              0,
              'Identifier is already in use as {}. did="{}"'.format(
                  d1_gmn.app.did.classify_identifier(sid), sid
              ),
              identifier=sid,
          )