DockerModuleHandle IllegalStateException checkEnded

When running DockerModuleHandleTest on Windows 10 inside VMWare Free player on Linux as host, I get "random" failures.. Seemingly simple HTTP requests from the DockerModuleHandle to the mock DockerServer will sometimes return null, due to an

IllegalStateException thrown in HttpClientResponseImpl.150 - method checkEnded.

The problem seems to be that the response has already been processed when the code tries to set exceptionHandler, endHandler etc..