The current behavior when the handler returns None is absolute close() as described in the docs.

@app.route('/')
async def hello_world():
    return None

I want to tweak it a little bit so that it respects keep-alive in the following case, because I see this looks "broken" in wrk benchmark but is actually not.

@app.route('/info')
async def hello_world(response):
    await response.sendfile('/path/to/file.txt', content_type='text/plain')
    # because of implicitly return None here

So for rensponse.end() to force close is to use keepalive=False:

    await response.end(b'Hello, World!', keepalive=False)

And that option was already available a long before, but useless. Now it is useful.