static XMLObject fromDeflatedBase64(String base64Encoded) {
        requireNonNull(base64Encoded, "base64Encoded");

        final byte[] base64decoded;
        try {
            base64decoded = Base64.getMimeDecoder().decode(base64Encoded);
        } catch (IllegalArgumentException e) {
            throw new InvalidSamlRequestException("failed to decode a deflated base64 string", e);
        }

        final ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
        try (InflaterOutputStream inflaterOutputStream =
                     new InflaterOutputStream(bytesOut, new Inflater(true))) {
            inflaterOutputStream.write(base64decoded);
        } catch (IOException e) {
            throw new InvalidSamlRequestException("failed to inflate a SAML message", e);
        }

        return SamlMessageUtil.deserialize(bytesOut.toByteArray());
    }
Decodes, inflates and deserializes the specified base64-encoded message to an {@link XMLObject}.
saml/src/main/java/com/linecorp/armeria/server/saml/HttpRedirectBindingUtil.java