      #     class TestSerializer(serializers.ModelSerializer):
      #         class Meta:
      #             model = ManyToManyTargetModel
      #             fields = ('id', 'name', 'reverse_many_to_many')
      #     print repr(TestSerializer()) 
</s> remove         class NestedModelSerializer(ModelSerializer):  # Not right!
 </s> add         class NestedModelSerializer(ModelSerializer): </s> remove             ret[field_name] = self.get_field(field)
 </s> add             ret[field_name] = self.get_field(field_name, field) </s> remove             ret[info.pk.name] = serializer_pk_field
 </s> add             ret[field_name] = serializer_pk_field </s> remove         serializer_pk_field = self.get_pk_field(info.pk)
 </s> add         field_name = info.pk.name
        serializer_pk_field = self.get_pk_field(field_name, info.pk) </s> remove                 ret[field_name] = self.get_nested_field(*relation_info)
 </s> add                 ret[field_name] = self.get_nested_field(field_name, *relation_info)
      #     class TestSerializer(serializers.ModelSerializer):
      #         class Meta:
      #             model = ManyToManyTargetModel
      #             fields = ('id', 'name', 'reverse_many_to_many')

keep keep keep keep replace
 Drop label from serializer fields when not needed 
tests/test_model_field_mappings.py