@Test
public void testSimpleCaseDual() {

	String[] constantFieldsFirst = { "1->1,2", "2->3" };
	String[] constantFieldsSecond = { "1->1,2", "2->3" };
	TypeInformation<?> type = new TupleTypeInfo<Tuple4<Integer, Integer, Integer, Integer>>(BasicTypeInfo.INT_TYPE_INFO,
			BasicTypeInfo.INT_TYPE_INFO, BasicTypeInfo.INT_TYPE_INFO, BasicTypeInfo.INT_TYPE_INFO);
	
	
	DualInputSemanticProperties dsp = new DualInputSemanticProperties();
	
	SemanticPropUtil.getSemanticPropsDualFromString(dsp, constantFieldsFirst, constantFieldsSecond, null,
			null, null, null, type, type, type);
	FieldSet fs = dsp.getForwardedField1(1);
	Assert.assertTrue(fs.size() == 2);
	Assert.assertTrue(fs.contains(1));
	Assert.assertTrue(fs.contains(2));
	fs = dsp.getForwardedField1(2);
	Assert.assertTrue(fs.size() == 1);
	Assert.assertTrue(fs.contains(3));
}