Jose\Algorithm\KeyEncryption\PBES2AESKW::checkHeaderAlgorithm PHP Method

    protected function checkHeaderAlgorithm(array $header)
    {
        Assertion::keyExists($header, 'alg', 'The header parameter "alg" is missing.');
        Assertion::notEmpty($header['alg'], 'The header parameter "alg" is not valid.');
    }