Youshido\GraphQL\Parser\Ast\Query::hasField PHP Method

    public function hasField($name, $deep = false)
    {
        foreach ($this->getFields() as $field) {
            if ($field->getName() == $name) {
                return true;
            }
            if ($deep && $field instanceof Query) {
                if ($field->hasField($name)) {
                    return true;
                }
            }
        }
        return false;
    }