private void deser(final byte[] fastInfosetBytes,
                       final ParserVocabulary parserVocabulary)
            throws FastInfosetException, IOException, SAXException {

        final SAXDocumentParser saxDocumentParser = new SAXDocumentParser();
        saxDocumentParser.setContentHandler(new LoggingHandler());
        if (parserVocabulary != null) {
            saxDocumentParser.setExternalVocabularies(Map.of(URI, parserVocabulary));
//            saxDocumentParser.setVocabulary();
        }
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(fastInfosetBytes);
        saxDocumentParser.parse(byteArrayInputStream);

        //https://github.com/pbielicki/fastinfoset-java/blob/master/samples/src/main/java/samples/sax/SAXParsingSample.java
    }
A proof of concept for https://github.com/gchq/stroom/issues/1945
Trying to prove that we can generate a fast infoset vocab
for some xml and then append to it. This is to reduce the volume of data
stored in the LMDB ref data store.
stroom-pipeline/src/test/java/stroom/pipeline/refdata/TestFastInfosetVocab.java