wp-includes/class-wp-user.php:707Updates the maximum user level for the user.
public function update_user_level_from_caps() { global $wpdb; $this->user_level = array_reduce( array_keys( $this->allcaps ), array( $this, 'level_reduction' ), 0 ); update_user_meta( $this->ID, $wpdb->get_blog_prefix() . 'user_level', $this->user_level ); }Introduced in 2.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-user.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.