@Override
    @SuppressWarnings("unchecked")
    protected <T extends AlgorithmParameterSpec> T engineGetParameterSpec(Class<T> aClass)
            throws InvalidParameterSpecException {
        if (aClass != IvParameterSpec.class) {
            throw new InvalidParameterSpecException(
                    "Incompatible AlgorithmParametersSpec class: " + aClass);
        }
        return (T) new IvParameterSpec(iv);
    }
An implementation of {@link java.security.AlgorithmParameters} that contains only an IV.  The
supported encoding formats are ASN.1 (primary) and RAW.
common/src/main/java/org/conscrypt/IvParameters.java