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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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