=head2 $self->prepare_read($c)
-prepare to read from the engine.
+Prepare to read by initializing the Content-Length from headers.
=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