wp-includes/SimplePie/src/Cache/File.php:147Set the last modified time to the current time
bool public function touch() { return @touch($this->name); }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/File.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.