VersionPress\Utils\ArrayUtils::map PHP Method

    public static function map($mapFn, $array)
    {
        return array_map(function ($key) use($mapFn, $array) {
            return $mapFn($array[$key], $key);
        }, array_keys($array));
    }

 /**
  * If entity type identified by $entityName defines an ID column, creates a mapping between WordPress ID and VPID
  * for all entities (db rows) of such type.
  *
  * @param string $entityName E.g., "post"
  */
 private function createVpidsForEntitiesOfType($entityName)
 {
     if (!$this->dbSchema->getEntityInfo($entityName)->usesGeneratedVpids) {
         return;
     }
     $idColumnName = $this->dbSchema->getEntityInfo($entityName)->idColumnName;
     $tableName = $this->dbSchema->getTableName($entityName);
     $prefixedTableName = $this->dbSchema->getPrefixedTableName($entityName);
     $entities = $this->database->get_results("SELECT * FROM {$prefixedTableName}", ARRAY_A);
     $entities = $this->replaceForeignKeysWithReferencesInAllEntities($entityName, $entities);
     $storage = $this->storageFactory->getStorage($entityName);
     $entities = array_filter($entities, function ($entity) use($storage) {
         return $storage->shouldBeSaved($entity);
     });
     $chunks = array_chunk($entities, 1000);
     foreach ($chunks as $entitiesInChunk) {
         $wordpressIds = array_column($entitiesInChunk, $idColumnName);
         $idPairs = [];
         foreach ($wordpressIds as $id) {
             $id = intval($id);
             if (!isset($this->idCache[$entityName], $this->idCache[$entityName][$id])) {
                 $this->idCache[$entityName][$id] = IdUtil::newId();
             }
             $idPairs[$id] = $this->idCache[$entityName][$id];
         }
         $sqlValues = join(', ', ArrayUtils::map(function ($vpId, $id) use($tableName) {
             return "('{$tableName}', {$id}, UNHEX('{$vpId}'))";
         }, $idPairs));
         $query = "INSERT INTO {$this->database->vp_id} (`table`, id, vp_id) VALUES {$sqlValues}";
         $this->database->query($query);
         $this->checkTimeout();
     }
 }