mpy.scipy.fft``.

    Examples
    --------
    We can register a new fft backend:

    >>> from scipy.fft import fft, register_backend, set_global_backend
    >>> class NoopBackend:  # Define an invalid Backend
    ...     __ua_domain__ = "numpy.scipy.fft"
    ...     def __ua_function__(self, func, args, kwargs):
    ...          return NotImplemented
    >>> set_global_backend(NoopBackend())  # Set the invalid backend as global
    >>> register_backend("scipy")  # Register a new backend
    >>> fft([1])  # The registered backend is called because the global backend returns `NotImplemented`
    array([1.+0.j])
    >>> set_global_backend("scipy")  # Restore global backend to default

    N)