code: def key_summary(keyjar, issuer):
      
      try:
          kbl = keyjar[issuer]
      except KeyError:
          return ''
      else:
          key_list = []
          for kb in kbl:
              for key in kb.keys():
                  if key.inactive_since:
                      key_list.append(
                          '*{}:{}:{}'.format(key.kty, key.use, key.kid))
                  else:
                      key_list.append(
                          '{}:{}:{}'.format(key.kty, key.use, key.kid))
          return ', '.join(key_list)
docs: Return a text representation of the keyjar.
  
      :param keyjar: A :py:class:`oidcmsg.key_jar.KeyJar` instance
      :param issuer: Which key owner that we are looking at
      :return: A text representation of the keys