public function lookup($migration_id, array
$source_id_values) { $results =
[];
$migrations =
$this->migrationPluginManager->
createInstances($migration_id);
if (!
$migrations) { if (is_array($migration_id)) { if (count($migration_id) != 1
) { throw new PluginException("Plugin IDs '" .
implode("', '",
$migration_id) . "' were not found."
);
} $migration_id =
reset($migration_id);
} throw new PluginNotFoundException($migration_id);
} foreach ($migrations as $migration) { if ($result =
$this->
doLookup($migration,
$source_id_values)) { $results =
array_merge($results,
$result);
} } return $results;
} /**
* Performs a lookup.
*
* @param \Drupal\migrate\Plugin\MigrationInterface $migration
* The migration upon which to perform the lookup.
* @param array $source_id_values
* The source ID values to look up.
*
* @return array
* An array of arrays of destination identifier values.
*
* @throws \Drupal\migrate\MigrateException
* Thrown when $source_id_values contains unknown keys, or the wrong number
* of keys.
*/