Cache/TagManager.php
public function invalidateTags($tags)
    {
        if (empty($tags) || !$this->isEnabled()) {
            return;
        }

        $tags = $this->encodeTags($tags);

        foreach ($tags as $tag) {
            if (!in_array($tag, $this->invalidateTags)) {
                $this->invalidateTags[] = $tag;
            }
        }
    }
public function invalidateTags($tags)
    {
        if (empty($tags) || !$this->isEnabled()) {
            return;
        }

        $tags = $this->encodeTags($tags);

        foreach ($tags as $tag) {
            if (!in_array($tag, $this->invalidateTags)) {
                $this->invalidateTags[] = $tag;
            }
        }
    }
Invalidates tags.

@param mixed $tags