doCreateStub example

if (count($migrations) !== 1) {
      throw new \LogicException(sprintf('Cannot stub derivable migration "%s". You must specify the id of a specific derivative to stub.', $migration_id));
    }
    $migration = reset($migrations);
    $source_id_keys = array_keys($migration->getSourcePlugin()->getIds());
    if (count($source_id_keys) !== count($source_ids)) {
      throw new \InvalidArgumentException('Expected and provided source id counts do not match.');
    }
    if (array_keys($source_ids) === range(0, count($source_ids) - 1)) {
      $source_ids = array_combine($source_id_keys, $source_ids);
    }
    $stub = $this->doCreateStub($migration, $source_ids, $default_values);

    // If the return from ::import is numerically indexed, and we aren't     // requesting the raw return value, index it associatively using the     // destination id keys.     if (($key_by_destination_ids !== FALSE) && array_keys($stub) === range(0, count($stub) - 1)) {
      $stub = array_combine(array_keys($migration->getDestinationPlugin()->getIds()), $stub);
    }
    return $stub;
  }

  /** * Creates a stub. * * @param \Drupal\migrate\Plugin\MigrationInterface $migration * The migration to use to create the stub. * @param array $source_ids * The source ids to map to the stub. * @param array $default_values * (optional) An array of values to include in the stub. * * @return array|bool * An array of destination ids for the stub. * * @throws \Drupal\migrate\MigrateException */