The program accepts a command line argument, it can be a net or a picture.
If it is a net, then instead of loading the last saved net, the program will open the net requested net. However, if the net does not exist, then you will end with no net loaded.
The name "nonet.net" is not important: it can be anything as soon as it does not exist! The idea is to start the program without loading a net!
Start the program with a shortcut, open the properties and just add a fictious name as argument.