@classmethod
def register(cls, n):
    """Return a 'register' of ``n`` QubitPlaceholders.

        >>> qs = QubitPlaceholder.register(8) # a qubyte
        >>> prog = Program(H(q) for q in qs)
        >>> address_qubits(prog).out()
        H 0
        H 1
        ...
        >>>

        The returned register is a Python list of QubitPlaceholder objects, so all
        normal list semantics apply.

        :param n: The number of qubits in the register
        """
    return [cls() for _ in range(n)]
