GuzzleHttp\Psr7\Response::withStatus PHP Method

    public function withStatus($code, $reasonPhrase = '')
    {
        $new = clone $this;
        $new->statusCode = (int) $code;
        if ($reasonPhrase == '' && isset(self::$phrases[$new->statusCode])) {
            $reasonPhrase = self::$phrases[$new->statusCode];
        }
        $new->reasonPhrase = $reasonPhrase;
        return $new;
    }

 public function testCanCreateNewResponseWithStatusAndReason()
 {
     $r = new Response(200);
     $r2 = $r->withStatus(201, 'Foo');
     $this->assertEquals(200, $r->getStatusCode());
     $this->assertEquals('OK', $r->getReasonPhrase());
     $this->assertEquals(201, $r2->getStatusCode());
     $this->assertEquals('Foo', $r2->getReasonPhrase());
 }