src/Leevel/Http/Request.php
public function server(?string $key = null, $defaults = null)
    {
        return $this->getItem('server', $key, $defaults);
    }
public function server(?string $key = null, $defaults = null)
    {
        return $this->getItem('server', $key, $defaults);
    }
取回 server.

@param string            $key
@param null|array|string $defaults

@return array|string