Jose\Algorithm\KeyEncryption\ECDHES::checkKey PHP Method

    private function checkKey(JWKInterface $key, $is_private)
    {
        Assertion::true($key->has('x'), 'The key parameter "x" is missing.');
        Assertion::true($key->has('crv'), 'The key parameter "crv" is missing.');
        switch ($key->get('crv')) {
            case 'P-256':
            case 'P-384':
            case 'P-521':
                Assertion::eq($key->get('kty'), 'EC', 'Wrong key type.');
                Assertion::true($key->has('y'), 'The key parameter "y" is missing.');
                break;
            case 'X25519':
                Assertion::eq($key->get('kty'), 'OKP', 'Wrong key type.');
                break;
            default:
                throw new \InvalidArgumentException(sprintf('The curve "%s" is not supported', $key->get('crv')));
        }
        if (true === $is_private) {
            Assertion::true($key->has('d'), 'The key parameter "d" is missing.');
        }
    }