migrate_drupal_migration_plugins_alter example

  public function testMigrationPluginAlter($type, array $migration_definitions, array $expected) {
    $this->makeNodeMigrateMapTable($type, '7');
    migrate_drupal_migration_plugins_alter($migration_definitions);
    $this->assertSame($expected, $migration_definitions);
  }

  /** * Data provider for testMigrationPluginAlter(). */
  public function providerMigrationPluginAlter() {
    $tests = [];

    $migrations = [
      // The 'system_site' migration is needed to get the legacy Drupal version.