private void extractXMPAsEmbeddedFile(TikaInputStream tis, String location)
            throws IOException, SAXException {
        if (tis == null) {
            return;
        }
        Metadata xmpMetadata = new Metadata();
        xmpMetadata.set(Metadata.CONTENT_TYPE, XMP_MEDIA_TYPE.toString());
        xmpMetadata.set(TikaCoreProperties.EMBEDDED_RESOURCE_TYPE,
                TikaCoreProperties.EmbeddedResourceType.METADATA.toString());
        xmpMetadata.set(PDF.XMP_LOCATION, location);
        if (embeddedDocumentExtractor.shouldParseEmbedded(xmpMetadata)) {
            parseMetadata(tis, xmpMetadata);
        }

    }
Format used for signature dates
TODO Make this thread-safe
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-pdf-module/src/main/java/org/apache/tika/parser/pdf/AbstractPDF2XHTML.java