Side effect on input! Complete the afw adding not
    present transitions and marking them as False.

    :param dict afw: input AFW.

def afw_completion(afw):
    """ Side effect on input! Complete the afw adding not
    present transitions and marking them as False.

    :param dict afw: input AFW.
    """

    for state in afw['states']:
        for a in afw['alphabet']:
            if (state, a) not in afw['transitions']:
                afw['transitions'][state, a] = 'False'
    return afw