src/Message/Response.php
private function setStatus($status, $reasonPhrase = '')
    {
        HttpCodes::check($status);
        $this->status = intval($status, 10);
        if ($reasonPhrase === '') {
            $this->reasonPhrase = HttpCodes::reasonPhraseFor($this->status);
        }
    }
private function setStatus($status, $reasonPhrase = '')
    {
        HttpCodes::check($status);
        $this->status = intval($status, 10);
        if ($reasonPhrase === '') {
            $this->reasonPhrase = HttpCodes::reasonPhraseFor($this->status);
        }
    }
Sets the response status code

@param int    $status
@param string $reasonPhrase