def test_empty_values(self):
field = TimezoneChoiceField(choices=ALL_CHOICES, required=False)
self.assertEqual(field.clean(''), '')
self.assertEqual(field.clean(None), '')
def test_coercing(self):
field = TimezoneChoiceField(choices=ALL_CHOICES)
self.assertEqual(field.clean(settings.TIME_ZONE),
pytz.timezone(settings.TIME_ZONE))