Please also write tests that cover (at a minimum) `get_template_path`, `get_all_orgs`, `get_value_for_org`, and `set_by_domain`. It would also be nice if you could write a test that works more at the integration level: use the Django test client to get the HTML for a page that should change depending on the active microsite, assert that some microsite-specific things are present in that HTML, assert that some things that they replace are not present, and assert that some things specific to a different microsite in the configuration are not present. Also assert that you can hit that same page without the microsite prefix in the URL, and that the original page is returned, without the microsite customizations.