// * entityhub:reference
ValueConverter<Reference> referenceConverter = new ReferenceConverter();
addTransformer(referenceConverter.getDataType(),
new ValueConverterTransformerAdapter<Reference>(referenceConverter,vf));
// * xsd:anyURI
ValueConverter<Reference> uriConverter = new AnyUriConverter();
addTransformer(uriConverter.getDataType(),
new ValueConverterTransformerAdapter<Reference>(uriConverter,vf));
// * entityhub:text
ValueConverter<Text> literalConverter = new TextConverter();
addTransformer(literalConverter.getDataType(),
new ValueConverterTransformerAdapter<Text>(literalConverter,vf));