protected function importMigration(Migration $migration) {
    // Run dependencies first.
    $dependencies = $migration->getMigrationDependencies();
    $required_ids = $dependencies['required'];
    if ($required_ids) {
      $required_migrations = $this->migrationManager->createInstances($required_ids);
      array_walk($required_migrations, [$this, 'importMigration']);
    }

    $message = new MigrateMessage();
    $executable = new MigrateExecutable($migration, $message);
    $executable->import();
  }