I tried to reproduce to file some bugs, but the docs Ron linked to and the datastore_test.py[1] they in turn link to don't do "import webtest", so I guess the docs have been updated recently.
A quick search suggests webtest is part of Pylons[2]. But Pylons isn't listed as a built-in third-party library[3]. So I'm not sure if there's anything to fix.
The Pylons Project is a larger organisation that maintains a lot of open source software, including webtest, Pylons is ALSO a web framework, but that is also unrelated to webtest.
In the authors case, webtest should have been installed separately, rather than using it from within the cherrypy source code, which seems to vendor webtest.
A quick search suggests webtest is part of Pylons[2]. But Pylons isn't listed as a built-in third-party library[3]. So I'm not sure if there's anything to fix.
1. https://github.com/GoogleCloudPlatform/python-docs-samples/b... 2. http://docs.pylonsproject.org/projects/webtest/en/latest/ 3. https://cloud.google.com/appengine/docs/python/tools/built-i...