'Returns a 13 digits Swiss SSN named AHV (German) or
AVS (French and Italian)
See: http://www.bsv.admin.ch/themen/ahv/00011/02185/'

@classmethod
def ssn(cls):

    def _checksum(digits):
        evensum = sum(digits[:(-1):2])
        oddsum = sum(digits[1::2])
        return ((10 - ((evensum + (oddsum * 3)) % 10)) % 10)
    digits = [7, 5, 6]
    digits += random.sample(range(10), 9)
    digits.append(_checksum(digits))
    digits = u''.join([str(d) for d in digits])
    ssn = ((((((digits[:3] + u'.') + digits[3:7]) + u'.') + digits[7:11]) + u'.') + digits[11:])
    return ssn
