code: def _pop_claims_from_payload(self):
          
          claims_in_payload = [k for k in self.payload.keys() if
                               k in registered_claims.values()]
          for name in claims_in_payload:
              self.registered_claims[name] = self.payload.pop(name)
docs: Check for registered claims in the payload and move them to the
          registered_claims property, overwriting any extant claims.