def _validate_algorithm(self, algorithm: str) -> None:
        """
        Ensure that the nominated algorithm is recognized, and that cryptography is installed for those
        algorithms that require it
        """
        if algorithm not in ALLOWED_ALGORITHMS:
            raise TokenBackendError(
                format_lazy(_("Unrecognized algorithm type '{}'"), algorithm)
            )

        if algorithm in algorithms.requires_cryptography and not algorithms.has_crypto:
            raise TokenBackendError(
                format_lazy(
                    _("You must have cryptography installed to use {}."), algorithm
                )
            )

        Ensure that the nominated algorithm is recognized, and that cryptography is installed for those
        algorithms that require it
        
rest_framework_simplejwt/backends.py