src/Message/Server/RequestUriFactory.php
private function getServerParam($name, $default = null)
    {
        $data = $this->request->getServerParams();
        if (array_key_exists($name, $data)) {
            $default = trim($data[$name]);
        }
        return $default;
    }
private function getServerParam($name, $default = null)
    {
        $data = $this->request->getServerParams();
        if (array_key_exists($name, $data)) {
            $default = trim($data[$name]);
        }
        return $default;
    }
Retrieve an request server parameter stored with provided name

If no match is found the default value is returned instead

@param string $name    $_SERVER super-global key name
@param null   $default

@return null|string