docs: def authenticate_credentials(self, userid, password):
          """
          Authenticate the userid and password against username and password.
          """
          credentials = {
              get_user_model().USERNAME_FIELD: userid,
              'password': password
          }
          user = authenticate(**credentials)
  
          if user is None:
              raise exceptions.AuthenticationFailed(_('Invalid username/password.'))
  
          if not user.is_active:
              raise exceptions.AuthenticationFailed(_('User inactive or deleted.'))
  
          return (user, None)