  from rest_framework import status
  from rest_framework.response import Response
  from rest_framework.request import clone_request
  from rest_framework.settings import api_settings
  import warnings
  
  
  def _get_validation_exclusions(obj, pk=None, slug_field=None, lookup_field=None):
      """
      Given a model instance, and an optional pk and slug field,
 
</s> remove def _get_validation_exclusions(obj, pk=None, slug_field=None, lookup_field=None):
 </s> add def _get_validation_exclusions(obj, lookup_field=None): </s> remove import warnings
 </s> add  </s> remove         lookup = view_kwargs.get(self.lookup_field, None)
        pk = view_kwargs.get(self.pk_url_kwarg, None)
        slug = view_kwargs.get(self.slug_url_kwarg, None)

        if lookup is not None:
            filter_kwargs = {self.lookup_field: lookup}
        elif pk is not None:
            filter_kwargs = {'pk': pk}
        elif slug is not None:
            filter_kwargs = {self.slug_field: slug}
        else:
            raise ObjectDoesNotExist()

 </s> add         lookup_value = view_kwargs[self.lookup_field]
        filter_kwargs = {self.lookup_field: lookup_value} </s> remove     include = []

    if pk:
        # Deprecated
 </s> add     if lookup_field == 'pk': </s> remove     return [field.name for field in obj._meta.fields if field.name not in include]
 </s> add     return [field.name for field in obj._meta.fields if field.name != lookup_field]
  from rest_framework import status
  from rest_framework.response import Response
  from rest_framework.request import clone_request
  from rest_framework.settings import api_settings

  
  
  def _get_validation_exclusions(obj, pk=None, slug_field=None, lookup_field=None):
      """
      Given a model instance, and an optional pk and slug field,
keep keep keep keep replace keep keep keep keep keep
 Remove `pk_url_field`, `slug_url_field`, `slug_field`.

Closes #1773. 
rest_framework/mixins.py