def _get_superclassnames(self, cn, namespace):
        """
        Get list of superclasses names from the class repository for the
        defined classname in the namespace.

        Returns in order of descending class hiearchy.
        """
        class_repo = self._get_class_repo(namespace)
        superclass_names = []
        if cn is not None:
            cnwork = cn
            while cnwork:
                cnsuper = class_repo[cnwork].superclass
                if cnsuper:
                    superclass_names.append(cnsuper)
                cnwork = cnsuper
            superclass_names.reverse()
        return superclass_names
Get list of superclasses names from the class repository for the
        defined classname in the namespace.

        Returns in order of descending class hiearchy.