public static function traverseWithCallback(\PHPParser_Node $ast, $callback)
 {
     $t = new self($callback);
     $t->traverse($ast);
 }
 public static function traverseWithCallback(\PHPParser_Node $root, CallbackInterface $callback, ScopeCreatorInterface $scopeCreator = null)
 {
     $t = new self($callback, $scopeCreator);
     $t->traverse($root);
 }