wp-includes/SimplePie/src/Cache/Memcached.php:121Remove the cache
bool public function unlink() { return $this->cache->delete($this->name, 0); }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/SimplePie/src/Cache/Memcached.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.