class D6TermNodeDeriver

class D6TermNodeDeriver extends DeriverBase implements ContainerDeriverInterface {
    use MigrationDeriverTrait;
    
    /**
     * The base plugin ID this derivative is for.
     *
     * @var string
     */
    protected $basePluginId;
    
    /**
     * The migration plugin manager.
     *
     * @var \Drupal\Component\Plugin\PluginManagerInterface
     */
    protected $migrationPluginManager;
    
    /**
     * D6TermNodeDeriver constructor.
     *
     * @param string $base_plugin_id
     *   The base plugin ID this derivative is for.
     * @param \Drupal\Component\Plugin\PluginManagerInterface $migration_plugin_manager
     *   The migration plugin manager.
     */
    public function __construct($base_plugin_id, PluginManagerInterface $migration_plugin_manager) {
        $this->basePluginId = $base_plugin_id;
        $this->migrationPluginManager = $migration_plugin_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, $base_plugin_id) {
        return new static($base_plugin_id, $container->get('plugin.manager.migration'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinitions($base_plugin_definition, $base_plugin_definitions = NULL) {
        try {
            foreach (static::getSourcePlugin('d6_taxonomy_vocabulary') as $row) {
                $source_vid = $row->getSourceProperty('vid');
                $definition = $base_plugin_definition;
                $definition['source']['vid'] = $source_vid;
                // migrate_drupal_migration_plugins_alter() adds to this definition.
                $this->derivatives[$source_vid] = $definition;
            }
        } catch (\Exception) {
            // It is possible no D6 tables are loaded so just eat exceptions.
        }
        return $this->derivatives;
    }

}