FieldSynchronizer::replaceFieldItems

protected function replaceFieldItems(&$field, $oldItems, $newItems)
{
	$itemIdMap = $this->getFieldItemMap($oldItems, $newItems);
	foreach($field['ITEMS'] as $keyId => $oldItem)
	{
		foreach($itemIdMap as $oldItemId => $newItemId)
		{
			if($oldItem['ID'] != $oldItemId)
			{
				continue;
			}

			$field['ITEMS'][$keyId]['ID'] = $newItemId;
		}
	}
}