[1.7.x] Fixed the previous commit for Python3.

from django.core.files.storage import FileSystemStorage

from django.db import models

from django.db.models.fields.files import ImageFieldFile, ImageField

from django.utils import six

class Foo(models.Model):

    c = models.IntegerField(choices=CHOICES, null=True)

class Counter:

class Counter(six.Iterator):

    def __init__(self):

        self.n = 1

    def __iter__(self):

        return self

    def next(self):  # Python 3: def __next__(self)

    def __next__(self):

        if self.n > 5:

            raise StopIteration

        else: