def confirm(token):
    """Continue any paused workflow.

        Confirmation may occur after the user confirms their
        subscription request, or their email address must be verified,
        or the moderator must approve the subscription request.

        :param token: A token matching a workflow.
        :type token: string
        :return: A 3-tuple is returned where the first element is the token
            hash, the second element is a ``TokenOwner`, and the third element
            is the subscribed member.  If the subscriber got subscribed
            immediately, the token will be None and the member will be
            an ``IMember``.  If the subscription is still being held, the token
            will be a hash and the member will be None.
        :rtype: (str-or-None, ``TokenOwner``, ``IMember``-or-None)
        :raises LookupError: when no workflow is associated with the token.
        """
