public function addFields($fields = [], $defaults = [])
    {
        foreach ($fields as $field) {
            if (is_string($field)) {
                $this->addField($field, $defaults);
                continue;
            }

            if (is_array($field) && isset($field[0])) {
                $name = $field[0];
                unset($field[0]);
                $this->addField($name, $field);
                continue;
            }
        }

        return $this;
    }