  from django.db import models
  from django.utils import six
  from django.utils.datastructures import SortedDict
  from collections import namedtuple
  from rest_framework.compat import clean_manytomany_helptext
  from rest_framework.fields import empty, set_value, Field, SkipField
  from rest_framework.settings import api_settings
  from rest_framework.utils import html, model_meta, representation
  import copy
 
</s> remove from rest_framework.utils import html, modelinfo, representation
 </s> add from rest_framework.utils import html, model_meta, representation </s> remove     #     print repr(TestSerializer()) </s> add  </s> remove                 ret[field_name] = self.get_nested_field(*relation_info)
 </s> add                 ret[field_name] = self.get_nested_field(field_name, *relation_info) </s> remove         return self.get_field(model_field)
 </s> add         return self.get_field(field_name, model_field) </s> remove     def get_pk_field(self, model_field):
 </s> add     def get_pk_field(self, field_name, model_field):
from django.utils.text import capfirst
  from django.db import models
  from django.utils import six
  from django.utils.datastructures import SortedDict
from django.utils.text import capfirst
  from collections import namedtuple
  from rest_framework.compat import clean_manytomany_helptext
  from rest_framework.fields import empty, set_value, Field, SkipField
  from rest_framework.settings import api_settings
  from rest_framework.utils import html, model_meta, representation
  import copy
keep keep add keep keep keep keep keep keep
 Drop label from serializer fields when not needed 
rest_framework/serializers.py