code: def add_kb(self, issuer, kb):
          
          try:
              self.issuer_keys[issuer].append(kb)
          except KeyError:
              self.issuer_keys[issuer] = [kb]
docs: Add a key bundle and bind it to an identifier
          
          :param issuer: Owner of the keys in the key bundle
          :param kb: A :py:class:`oidcmsg.key_bundle.KeyBundle` instance