public function getResponseClass($statusCode)
{
$responseClass = [1 => self::CLASS_INFORMATIONAL, 2 => self::CLASS_SUCCESS, 3 => self::CLASS_REDIRECTION, 4 => self::CLASS_CLIENT_ERROR, 5 => self::CLASS_SERVER_ERROR];
$statusCode = $this->filterStatusCode($statusCode);
return $responseClass[(int) substr($statusCode, 0, 1)];
}