Rollback a subset idlist of a specific Drupal 7 migration

RollbackMigrationIdList.php

<?php 

/**
 * Rollback only 'articles' type nodes using the idlist option 
 * This is useful if you can't for some reason rollback the whole migration
 */
function migration_update_7001() {
  // Get the 'migrate' database and query for nodes that should not have been
  // in our migration class - 52 is the term id for 'articles' 
  $results = Database::getConnection('default', 'migrate')
    ->query('SELECT *
           FROM field_data_field_type fdft
           WHERE fdft.field_type_tid = 52 
           ORDER BY fdft.entity_id;');
  $article_nids = $results->fetchAllAssoc('entity_id');
  echo 'Rolling back ' . count($article_nids) . ' article Pages.';
  $idlist = implode(',', array_keys($article_nids));
  // rollback only the 'articles' types from the migration using 'idlist' option
  migrate_static_registration(array('NARPage'));
  $migration = Migration::getInstance('NARPage');
  $result = $migration->processRollback(array('idlist' => $idlist));
}