Bitrix tagged caching

tagged_cache.php

<?php
// Source example comes from https://dev.1c-bitrix.ru/learning/course/index.php?COURSE_ID=43&LESSON_ID=2978

$cacheTime = 10;
$cacheId = 'cache_id_comes_here';
$cacheDir = '/some_tag_cache/subsubdir';

/* D7 version */
$cache = Bitrix\Main\Data\Cache::createInstance();
if ($cache->initCache($cacheTime, $cacheId, $cacheDir))
{
    echo 'Values are taken from cache: <br />';

    $result = $cache->getVars();
}
elseif ($cache->startDataCache())
{
    echo 'Values will be selected: <br />';

    $result = [];
    $dbItems = CIBlockElement::GetList(
        array('SORT' => 'ASC'),
        array(
            'IBLOCK_ID' => 1,
            'ACTIVE' => 'Y',
        ),
        false,
        ['nTopCount' => 2],
        ['ID', 'NAME', 'IBLOCK_ID']
    );

    $GLOBALS['CACHE_MANAGER']->StartTagCache($cacheDir);
    while ($row = $dbItems->Fetch()) {
        $GLOBALS['CACHE_MANAGER']->RegisterTag('iblock_id_' . $row['IBLOCK_ID']);
        $result[] = $row;
    }
    $GLOBALS['CACHE_MANAGER']->EndTagCache();

    $cache->endDataCache($result);
}


/* Old core version */
$cache = new CPHPCache();
if ($cache->InitCache($cacheTime, $cacheId, $cacheDir))
{
    echo 'Values are taken from cache: <br />';

    $result = $cache->GetVars();
}
elseif($cache->StartDataCache())
{
    echo 'Values will be selected: <br />';

    $result = [];
    $dbItems = CIBlockElement::GetList(
        array('SORT' => 'ASC'),
        array(
            'IBLOCK_ID' => 1,
            'ACTIVE' => 'Y',
        ),
        false,
        ['nTopCount' => 4],
        ['ID', 'NAME', 'IBLOCK_ID']
    );

    $GLOBALS['CACHE_MANAGER']->StartTagCache($cacheDir);
    while ($row = $dbItems->Fetch()) {
        $GLOBALS['CACHE_MANAGER']->RegisterTag('iblock_id_' . $row['IBLOCK_ID']);
        $result[] = $row;
    }
    /* Don't know what this line means, though it's still working without it */
    $GLOBALS['CACHE_MANAGER']->RegisterTag('iblock_id_new');

    $GLOBALS['CACHE_MANAGER']->EndTagCache();

    $cache->EndDataCache($result);
}

echo'<pre>Result is: ',print_r($result),'</pre>';