      def default_response_headers(self):
          # TODO: Only vary by accept if multiple renderers
          return {
              'Allow': ', '.join(self.allowed_methods),
              'Vary': 'Accept'
          }
  
      def http_method_not_allowed(self, request, *args, **kwargs):
          """
          If `request.method` does not correspond to a handler method,
 
</s> remove         # TODO: Only vary by accept if multiple renderers
        return {
 </s> add         headers = {
      def default_response_headers(self):
          # TODO: Only vary by accept if multiple renderers
          return {
              'Allow': ', '.join(self.allowed_methods),

          }
  
      def http_method_not_allowed(self, request, *args, **kwargs):
          """
          If `request.method` does not correspond to a handler method,
keep keep keep keep replace keep keep keep keep keep
 Only add 'Vary: Accept' header when there is more than one possible renderer. 
rest_framework/views.py