wp-includes/class-wp-roles.php:281Retrieves a list of role names.
string[] public function get_names() { return $this->role_names; }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-roles.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.