wp-includes/class-wp-object-cache.php:572Removes all cache items in a group.
$groupstringtrue public function flush_group( $group ) { unset( $this->cache[ $group ] ); return true; }Introduced in 6.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-object-cache.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.