          # HyperlinkedModelSerializer set it on-the-fly
          self.view_name = kwargs.pop('view_name', None)
          # Optionally the format of the target hyperlink may be specified
          self.format = kwargs.pop('format', None)
  
          self.lookup_field = kwargs.pop('lookup_field', self.lookup_field)
  
          # These are pending deprecation
          if 'pk_url_kwarg' in kwargs:
              msg = 'pk_url_kwarg is pending deprecation. Use lookup_field instead.'
              warnings.warn(msg, PendingDeprecationWarning, stacklevel=2)
 
</s> remove from rest_framework.response import Response
from rest_framework import viewsets
 </s> add from rest_framework import serializers, viewsets
from rest_framework.compat import include, patterns, url
        lookup_field = kwargs.pop('lookup_field', None)
        if lookup_field is not None:
            self.lookup_field = lookup_field
          # HyperlinkedModelSerializer set it on-the-fly
          self.view_name = kwargs.pop('view_name', None)
          # Optionally the format of the target hyperlink may be specified
          self.format = kwargs.pop('format', None)
        lookup_field = kwargs.pop('lookup_field', None)
        if lookup_field is not None:
            self.lookup_field = lookup_field
        lookup_field = kwargs.pop('lookup_field', None)
        if lookup_field is not None:
            self.lookup_field = lookup_field
  
          # These are pending deprecation
          if 'pk_url_kwarg' in kwargs:
              msg = 'pk_url_kwarg is pending deprecation. Use lookup_field instead.'
              warnings.warn(msg, PendingDeprecationWarning, stacklevel=2)
keep keep keep keep replace replace keep keep keep keep keep
 HyperlinkedModelSerializer lookup_field option should apply to HyperlinkedIdentityField 
rest_framework/relations.py