AttributeError: 'Assign' object has no attribute 'getChildNodes'

[kmmbvnr]

File "/home/kmmbvnr/Projects/wthr.cc/mobistyle/env/local/lib/python2.7/site-packages/DjangoLint/AstCheckers/model_fields.py", line 100, in visit_callfunc
x = node.parent.getChildNodes()[0]
AttributeError: 'Assign' object has no attribute 'getChildNodes'

And here is the file content:

from django.db import models

class TheModel(models.Model):
slug = models.SlugField(primary_key=True)