code: def get_jwt_verify_keys(self, jwt, **kwargs):
          
  
          try:
              allow_missing_kid = kwargs['allow_missing_kid']
          except KeyError:
              allow_missing_kid = False
  
          try:
              _key_type = jws_alg2keytype(jwt.headers['alg'])
          except KeyError:
              _key_type = ''
  
          try:
              _kid = jwt.headers['kid']
          except KeyError:
              logger.info('Missing kid')
              _kid = ''
  
          try:
              nki = kwargs['no_kid_issuer']
          except KeyError:
              nki = {}
  
          _payload = jwt.payload()
  
          try:
              _iss = _payload['iss']
          except KeyError:
              try:
                  _iss = kwargs['iss']
              except KeyError:
                  _iss = ''
  
          if _iss:
              # First extend the key jar iff allowed
              if "jku" in jwt.headers and _iss:
                  if not self.find(jwt.headers["jku"], _iss):
                      # This is really questionable
                      try:
                          if kwargs["trusting"]:
                              self.add_url(_iss, jwt.headers["jku"])
                      except KeyError:
                          pass
  
              keys = self._add_key([], _iss, 'sig', _key_type,
                                   _kid, nki, allow_missing_kid)
  
              if _key_type == 'oct':
                  keys.extend(self.get(key_use='sig', owner='',
                                       key_type=_key_type))
          else:  # No issuer, just use all keys I have
              keys = self.get(key_use='sig', owner='', key_type=_key_type)
  
          # Only want the appropriate keys.
          keys = [k for k in keys if k.appropriate_for('verify')]
          return keys
docs: Get keys from this key jar based on information in a JWS. These keys
          should be usable to verify the signed JWT.
  
          :param jwt: A cryptojwt.jwt.JWT instance
          :param kwargs: Other key word arguments
          :return: list of usable keys