@Test
public void testWriteItemDocumentWithNullPropertyTypes() throws RDFHandlerException,
		IOException, RDFParseException {

	this.rdfConverter = new RdfConverter(this.rdfWriter, this.sites,
			new MockPropertyRegister.WithNullPropertyTypes());
	ItemDocument document = this.objectFactory.createItemDocument();
	this.rdfConverter.writeItemDocument(document);
	this.rdfWriter.finish();
	Model model = RdfTestHelpers.parseRdf(out.toString());
	assertEquals(model, RdfTestHelpers.parseRdf(RdfTestHelpers
			.getResourceFromFile("ItemDocumentUnknownPropertyTypes.rdf")));
}