Doctrine\OrientDB\Binding\Client\Http\CurlClientResponse::getHeader PHP Method

    public function getHeader($header)
    {
        return isset($this->headers[$header]) ? $this->headers[$header] : null;
    }

 public function testnullIsReturnedWhenRequestingANonExistingHeader()
 {
     $response = new CurlClientResponse("HTTP/1.1 200 OK\r\nCache-Control: max-age=30\r\nCache-Control: s-maxage=50\r\n\r\n");
     $this->assertEquals(null, $response->getHeader('Host'));
 }