Any concrete example of 'hplus generate -f <file>'?

[Dev-XYS]

I'm interested in your project and want to try out. I have successfully installed the Docker image, built the project, and I am able to run the Maybe example in the readme. However, I have difficulty generating my own component library. I wonder what file format we should pass to -f. I've tried a regular Haskell source file but that didn't work. I think it will be more clear if a concrete example is given.