@SuppressWarnings("unchecked")
    public static Map<String, String> getPrefixes() {
        return registry.getPrefixes();
    }
@return Returns the registered namespace/prefix-pairs as map, where the keys are the prefixes
and the values are the namespaces.
tika-xmp/src/main/java/org/apache/tika/xmp/XMPMetadata.java