assertTrue("Wrong value of optional attribute", decl.isOptional());
config.addProperty("xml[@optional]", "false");
decl = createDeclaration(config.configurationAt("xml"));
assertTrue("Wrong value of config-optional attribute",
decl.isOptional());
config.clearProperty("xml[@config-optional]");
config.setProperty("xml[@optional]", Boolean.TRUE);
decl = createDeclaration(config.configurationAt("xml"));
assertTrue("Old optional attribute not detected", decl.isOptional());
}