/**
* 构造方法
* @param string $question 问题
* @param array $choices 选项
* @param mixed $default 默认答案
*/
public function __construct($question, array $choices, $default = null)
{
parent::__construct($question, $default);
$this->choices = $choices;
$this->setValidator($this->getDefaultValidator());
$this->setAutocompleterValues($choices);
}