// Add a row needing update and assert multiple imported rows.
$source = ['source_id_property' => 'source_value_update'];
$row = new Row($source, ['source_id_property' => []]);
$destination = ['destination_id_property' => 'destination_value_update'];
$id_map->saveIdMapping($row, $destination, MigrateIdMapInterface::STATUS_NEEDS_UPDATE);
// Add a row needing update and assert multiple imported rows.
$source = ['source_id_property' => 'source_value_update'];
$row = new Row($source, ['source_id_property' => []]);
$destination = ['destination_id_property' => 'destination_value_update'];
$id_map->saveIdMapping($row, $destination, MigrateIdMapInterface::STATUS_NEEDS_UPDATE);