ToplevelList system = cdlDocument.getSystem();
SystemElement system = cdlDocument.getSystem();
    public void testExtendsAttributeInheritance() throws IOException, CdlException,            ParsingException {        ParseContext context = new ParseContext();        CdlDocument cdlDocument = parseValidCDL(context,                CDL_DOC_ATTRIBUTE_INHERITANCE);        //xpath tests to verify the stuff        ToplevelList system = cdlDocument.getSystem();        PropertyList child = system.getChildTemplateMatching(                new QName("child"));        assertHasAttribute(child, "attr_a2");        assertAttributeValueEquals(child, "attr_a3", "a3");        assertAttributeValueEquals(child, "attr_a1", "a1");        assertHasAttribute(child, "attr_system");    }