def METHOD_NAME(self):
    f = ContentFile(b'eloziom', name='foo')
    model = FileTestModel()
    model.file_field = f
    model.save()
    pk = model.pk
    # Here the model is removed from Django's cache, so the query
    # below actually hits the database.
    del model
    model = FileTestModel.objects.get(pk=pk)
    self.assertEqual(model.file_field.read(), b'eloziom')
    model.file_field.delete()