framework/web/Request.php
public function getETags()
    {
        if ($this->headers->has('If-None-Match')) {
            return preg_split('/[\s,]+/', str_replace('-gzip', '', $this->headers->get('If-None-Match')), -1, PREG_SPLIT_NO_EMPTY);
        }

        return [];
    }
public function getETags()
    {
        if ($this->headers->has('If-None-Match')) {
            return preg_split('/[\s,]+/', str_replace('-gzip', '', $this->headers->get('If-None-Match')), -1, PREG_SPLIT_NO_EMPTY);
        }

        return [];
    }
Gets the Etags.

@return array The entity tags