PKCE: Unset oauth2pkceCode from session after login?

[Hannes Kirsman]

There's this example in dev release for PKCE

// Store the PKCE code after the `getAuthorizationUrl()` call.
$_SESSION['oauth2pkceCode'] = $provider->getPkceCode();
// ...
// Restore the PKCE code before the `getAccessToken()` call. 
$provider->setPkceCode($_SESSION['oauth2pkceCode']);

What about unsettling the $_SESSION['oauth2pkceCode'] after setPkceCode() is done?

unset($_SESSION['oauth2pkceCode']);

There's no reason to keep it around, is there?