interface MigrateExecutableInterface

interface MigrateExecutableInterface {
    
    /**
     * Performs an import operation - migrate items from source to destination.
     *
     * @return int
     *   Returns a value indicating the status of the import operation.
     *   The possible values are the 'RESULT_' constants defined
     *   in MigrationInterface.
     *
     * @see \Drupal\migrate\Plugin\MigrationInterface
     */
    public function import();
    
    /**
     * Performs a rollback operation - remove previously-imported items.
     */
    public function rollback();
    
    /**
     * Processes a row.
     *
     * @param \Drupal\migrate\Row $row
     *   The $row to be processed.
     * @param array $process
     *   (optional) A process pipeline configuration. If not set, the top level
     *   process configuration in the migration entity is used.
     * @param mixed $value
     *   (optional) Initial value of the pipeline for the first destination.
     *   Usually setting this is not necessary as $process typically starts with
     *   a 'get'. This is useful only when the $process contains a single
     *   destination and needs to access a value outside of the source. See
     *   \Drupal\migrate\Plugin\migrate\process\SubProcess::transformKey for an
     *   example.
     *
     * @throws \Drupal\migrate\MigrateException
     */
    public function processRow(Row $row, array $process = NULL, $value = NULL);
    
    /**
     * Passes messages through to the map class.
     *
     * @param string $message
     *   The message to record.
     * @param int $level
     *   (optional) Message severity (defaults to MESSAGE_ERROR).
     */
    public function saveMessage($message, $level = MigrationInterface::MESSAGE_ERROR);

}