public function addChoices($choices)
    {
        if (func_num_args() > 1) {
            $choices = func_get_args();
        }

        foreach ($choices as $key => $value) {
            $label = $choice = $value;

            if (is_array($choice)) {
                $label = array_values($choice)[0];
                $choice = array_keys($choice)[0];
            } else if (is_string($key)) {
                $choice = $key;
                $label = $value;
            }

            $this->addChoice($choice, $label);
        }

        return $this;
    }