assertFalse("Found an optional attribute", decl.isOptional());
config.addProperty("xml[@config-at]", "test1");
decl = createDeclaration(config.configurationAt("xml"));
assertEquals("Wrong value of at attribute", "test1", decl.getAt());
config.addProperty("xml[@at]", "test2");
decl = createDeclaration(config.configurationAt("xml"));
assertEquals("Wrong value of config-at attribute", "test1",
decl.getAt());
config.clearProperty("xml[@config-at]");
decl = createDeclaration(config.configurationAt("xml"));
assertEquals("Old at attribute not detected", "test2", decl.getAt());