During development, changing backend code causes Sidekiq to reload and
spew, "A copy of Gitlab::SidekiqMiddleware::AdminMode::Client has been
removed from the module tree but is still active!" errors.

To fix this, https://stackoverflow.com/a/29710188 mentions adding `::`
to `Example` helps because this causes `Object.const_missing` instead of
`Example.const_missing`.