In message <1613143109.77.0.35134070202.issue2551112@roundup.psfhosted.org>,
Christof Meerwald writes:
>Yes, moving it to a "preload" method would definitely be an improvement.

I am fine with that. Ralf any ideas on how to add this file to the
test suite? We have 0 lines of coverage there, so anything would be
good.

>Another option could be to have a base class you can derive from that 
>doesn't have the "preload" functionality. Either option would work for 
>me.

I don't think cluttering the code with a new RequestDispatcherBase
class and then creating:

  RequestDispatcher(RequestDispatcherBase):

     def __init__(...):

     def preload(...):

with just these two (or just __init__) methods is warranted.