def METHOD_NAME(self, other: "AbstractHilbert") -> "AbstractHilbert":
    """This function can be implemented by subclasses to
    specify how to multiply two Hilbert spaces of the same type.
    This can be used as an optimization to avoid creating a TensorHilbert
    object when possible, instead returning a new Hilbert space type.
    If it is not possible to combine the two Hilbert spaces,
    it should return NotImplemented.
    Args:
        other: other Hilbert space to combine with.
    Returns:
        An Hilbert space combining the two.
    """
    return NotImplemented