wp-includes/SimplePie/src/Cache/MySQL.php:330Retrieve the last modified time for the cache
int public function mtime() { if ($this->mysql === null) { return false; } $query = $this->mysql->prepare('SELECT `mtime` FROM `' . $this->options['extras']['prefix'] . 'cache_data` WHERE `id` = :id'); $query->bindValue(':id', $this->id); if ($query->execute() && ($time = $query->fetchColumn())) { return $time; } return false; }One change between 6.7.7 and 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
int to int|false.verified against sourcesrc/wp-includes/SimplePie/src/Cache/MySQL.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.