anonymous function using arguments with parent fn's variables

gistfile1.aw

public function parentFn($argVar) {
  $decVar = 0.00;
  
  $callback = function ($anonVar) use ($argVar, &$decVar) {
    $result += ($decVar * $anonVar) * ($argVar);
  };
  
  return round($result, 2);
}