Cocosbuilder custom property loading problem

From CCNodeLoader::parseProperties, looks like custom property set in Cocosbuilder are not handled. Am I overlooking?

it’d assert fail for any custom property:

void CCNodeLoader::onHandlePropTypeInteger(CCNode * pNode, CCNode * pParent, CCString * pPropertyName, int pInteger, CCBReader * pCCBReader) {
if(pPropertyName~~>compare == 0) {
pNode~~>setTag(pInteger);
} else {
ASSERT_FAIL_UNEXPECTED_PROPERTY(pPropertyName);
}
}

if not, what’s the proper way to add custom property? thanks!