=head2 $self->prepare_request(@arguments)
-Populate the context object from the request object.
+Sets up the PSGI environment in the Engine.
=cut
=head2 build_psgi_app ($app, @args)
-Builds and returns a PSGI application closure, wrapping it in the reverse proxy
-middleware if the using_frontend_proxy config setting is set.
+Builds and returns a PSGI application closure. (Raw, not wrapped in middleware)
=cut