@Test
public void testPropertyDocumentToJson() {

	PropertyDocument pd = Datamodel.makePropertyDocument(
			Datamodel.makeWikidataPropertyIdValue("P1"),
			Collections. emptyList(),
			Collections. emptyList(),
			Collections. emptyList(),
			Collections. emptyList(),
			Datamodel.makeDatatypeIdValue(DatatypeIdValue.DT_ITEM));
	String json = "{\"id\":\"P1\",\"aliases\":{},\"labels\":{},\"descriptions\":{},\"claims\":{},\"type\":\"property\", \"datatype\":\"wikibase-item\"}";
	JsonComparator.compareJsonStrings(json, JsonSerializer.getJsonString(pd));
}