What is the module "Layout"?

Hi Popoff, 
Thanks for you demo to illustrate DMD for phase control via lee hologram.
Module "Layout" is widely used in the demo, what's weird is that I can't seem to use it, neither can I find it in PyPI  or download it via pip. Is the module written by you? If so, would you mind sharing it here?

Best
Shengfu Cheng 