private static Set<MediaType> readMimeTypes(Element mimeTypes) {
        Set<MediaType> types = new HashSet<>();

        NodeList children = mimeTypes.getChildNodes();
        for (int i = 0; i < children.getLength(); i++) {
            Node node = children.item(i);
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                Element child = (Element) node;
                if (child.getTagName().equals(MIMETYPE_TAG)) {
                    types.add(MediaType.parse(getString(child)));
                }
            }
        }

        return types;
    }
Builds and Returns an ExternalParser, or null if a check
command was given that didn't match.
tika-core/src/main/java/org/apache/tika/parser/external/ExternalParsersConfigReader.java