Type: Documentation-only
[response.finished][] indicates whether [response.end()][] has been
called, not whether 'finish' has been emitted and the underlying data
is flushed.
Use [response.writableFinished][] or [response.writableEnded][]
accordingly instead to avoid the ambigiuty.
To maintain existing behaviour response.finished should be replaced with
response.writableEnded.
