@SuppressWarnings("unchecked")
@Test
public void testFilter9()
                        throws XMLStreamException, FactoryConfigurationError, IOException {

    Filter result = parse( "v100/testfilter9.xml" );
    OperatorFilter opFilter = (OperatorFilter) result;
    PropertyIsEqualTo prop = (PropertyIsEqualTo) opFilter.getOperator();
    ValueReference propName = (ValueReference) prop.getParameter1();
    assertEquals( "PROPA", propName.getAsText() );
    Add add = (Add) prop.getParameter2();
    ValueReference propB = (ValueReference) add.getParameter1();
    assertEquals( "PROPB", propB.getAsText() );
    Literal<PrimitiveValue> lit = (Literal<PrimitiveValue>) add.getParameter2();
    assertEquals( "100", lit.getValue().toString() );
}