src/Cache/ArrayCache.php
protected function addKeyTags($key, $tags = [])
    {
        foreach ($tags as $tag) {
            if (!isset($this->tags[$tag])) {
                $this->tags[$tag] = [];
            }
            $this->tags[$tag][$key] = $key;
        }
    }
protected function addKeyTags($key, $tags = [])
    {
        foreach ($tags as $tag) {
            if (!isset($this->tags[$tag])) {
                $this->tags[$tag] = [];
            }
            $this->tags[$tag][$key] = $key;
        }
    }
Save key tags
@param string   $key
@param string[] $tags