Exception generated during request completion

I am seeing the error below in the twisted.log file for my Klein-based microservice. It looks as though there could be a race condition with the channel have being deleted prior to the cleanup call. Has anyone else seen this kind of behavior?

Thanks. Peter

2020-05-15 22:37:37+0000 [-] Unhandled Error writing response
        Traceback (most recent call last):
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/twisted/internet/defer.py", line 1475, in gotResult
            _inlineCallbacks(r, g, status)
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/twisted/internet/defer.py", line 1421, in _inlineCallbacks
            status.deferred.callback(getattr(e, "value", None))
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/twisted/internet/defer.py", line 460, in callback
            self._startRunCallbacks(result)
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/twisted/internet/defer.py", line 568, in _startRunCallbacks
            self._runCallbacks()
        --- <exception caught here> ---
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/twisted/internet/defer.py", line 654, in _runCallbacks
            current.result = callback(current.result, *args, **kw)
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/klein/_resource.py", line 282, in write_response
            request.finish()
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/twisted/web/server.py", line 248, in finish
            return http.Request.finish(self)
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/twisted/web/http.py", line 1064, in finish
            self._cleanup()
          File "/home1/aim-user/anaconda3/envs/visual_page_classifier/lib/python3.6/site-packages/twisted/web/http.py", line 756, in _cleanup
            self.channel.requestDone(self)
        builtins.AttributeError: 'NoneType' object has no attribute 'requestDone'

Start with klein/_resource.py at write_response and trace the request lifecycle shown through Twisted's server.py and http.py. The report provides no reproduction steps or test location, so first establish when the channel becomes None; done would require a reproducible case and a verified fix or regression test for request completion.