Mock a HTTP request that times out with HTTPretty

Using the HTTPretty library for Python, I can create mock HTTP responses of choice and then pick them up i.e. with the requests library like so:

import httpretty
import requests

# set up a mock
httpretty.enable()
httpretty.register_uri(
            method=httpretty.GET,
            uri='http://www.fakeurl.com',
            status=200,
            body='My Response Body'
        )

response = requests.get('http://www.fakeurl.com')

# clean up
httpretty.disable()
httpretty.reset()

print(response)

Out: <Response [200]>

Is there also the possibility to register an uri which cannot be reached (e.g. connection timed out, connection refused, ...) such that no response is received at all (which is not the same as an established connection which gives an HTTP error code like 404)?

I want to use this behaviour in unit testing to ensure that my error handling works as expected (which does different things in case of 'no connection established' and 'connection established, bad bad HTTP status code'). As a workaround, I could try to connect to an invalid server like http://192.0.2.0 which would time out in any case. However, I would prefer to do all my unit testing without using any real network connections.