TL;DR
A box that you place on the ground which can contain other circuit combinators and allows you to hide the complexity of the design and better document how it works and should be used.What ?
It's circuit combinator that when placed in the world looks like a 2x2 box with 2 green and 2 red inputs, and 1 and 1 green outputs. It doesn't do anything by itself, but you can open it and place other circuit combinators inside. This allows you to hide the complexity of the circuitry and only present a few inputs/outputs to the player in a standardized format.While viewing the wrapper's insides, you can also place "comments" to explain how different parts work. A comment is a short text label outside the buildable grid, and an arrow pointing to one of the tiles. This allows a more detailed documentation.
The wrapper has functionality to make it visually distinct. You can set a signal icon that will be displayed on the box. You can set the color of the box. Maybe it even has a little light with configurable color. This helps a player look at a wrapper and immediately recognize what type it is.
The wrapper is similar to the concept of wrapper in programming and it also helps documenting complex circuits.
Why ?
It solves several problems with the circuit combinators.1. Lack of documentation outside of blueprints. Complex circuits are also hard to document with text only.
2. Can't tell at a glance what several circuit combinators wired to each other do, or where the inputs and outputs are.
3. No way to hide irrelevant complexity.
