          """
          Set the `.action` attribute on the view,
          depending on the request method.
          """
          request = super(ViewSetMixin, self).initialize_request(request, *args, **kargs)
          self.action = self.action_map.get(request.method.lower())
          return request
  
  
  class ViewSet(ViewSetMixin, views.APIView):
 
</s> remove     def initialize_request(self, request, *args, **kargs):
 </s> add     def initialize_request(self, request, *args, **kwargs): </s> remove         raise ImproperlyConfigured('Returned a template response with no `template_name` attribute set on either the view or response')
 </s> add         raise ImproperlyConfigured(
            'Returned a template response with no `template_name` attribute set on either the view or response'
        ) </s> remove     don't need to dig into the implemention.
 </s> add     don't need to dig into the implementation. </s> remove         # The suffix initkwarg is reserved for identifing the viewset type
 </s> add         # The suffix initkwarg is reserved for identifying the viewset type </s> remove from django.core.exceptions import ImproperlyConfigured
from django.core.exceptions import ValidationError as DjangoValidationError
 </s> add import warnings

        request = super(ViewSetMixin, self).initialize_request(request, *args, **kwargs)
          """
          Set the `.action` attribute on the view,
          depending on the request method.
          """
        request = super(ViewSetMixin, self).initialize_request(request, *args, **kwargs)
          self.action = self.action_map.get(request.method.lower())
          return request
  
  
  class ViewSet(ViewSetMixin, views.APIView):
keep keep keep keep replace keep keep keep keep keep
 Removed unused imports, pep8 fixes, typo fixes 
rest_framework/viewsets.py