'Generate and return data for `num` tested on platforms'

def _platforms(self, num, device_types=[u'\xd0esktop', u'FirefoxOS'], devices=[u'PC    ', u'ZT\xc8    Open'], versions=[u'34', u'1.3<']):

    data = {}
    if (num > 0):
        for n in xrange(num):
            i = (n % len(device_types))
            data.update({('testedon-%d-device_type' % n): device_types[i], ('testedon-%d-device' % n): devices[i], ('testedon-%d-version' % n): versions[i]})
    return data
