@Test
public void testObjectVar() {

	builder.addPrefix("", "http://example/")
			.addWhere(":S", ":P", "?o");
	String query = builder.buildString();
	assertContainsRegex(WHERE + OPEN_CURLY + ":S" + SPACE + ":P" + SPACE
			+ var("o") + OPT_SPACE +  CLOSE_CURLY, query);
}