REQUIRED
REQUIRED = 1
__construct(string $name, int $mode = null, string $description = '', mixed $default = null) : mixed
构造方法
| string | $name | 参数名 |
| int | $mode | 参数类型: self::REQUIRED 或者 self::OPTIONAL |
| string | $description | 描述 |
| mixed | $default | 默认值 (仅 self::OPTIONAL 类型有效) |