code: def get_user_by_token(self, token):
          
          if not self.jwt_loader_implementation:
              return self.default_token_user_loader(token)
  
          try:
              implementation = import_string(self.jwt_loader_implementation)
          except ImportError:
              msg = 'Failed to import custom JWT user loader implementation. '
              msg += 'Check that configured module exists [{}]'
              raise x.ConfigurationException(
                  msg.format(self.jwt_loader_implementation)
              )
  
          # return user from custom loader
          return implementation(token)
docs: Get user by token
          Using for logging in. Check to see if a custom token user loader was
          registered and uses that. Otherwise falls back to default loader
          implementation. You should be fine with default implementation as long
          as your token has user_id claim in it.
  
          :param token: str, user token
          :return: boiler.user.models.User