Function command_in 

pub fn command_in(width: usize, mode: ColorMode) -> Command

The same tree again, at a width and in a color mode the caller states.

command_at is this with the mode read off standard output, which is the only place that reading happens. A caller that states the mode gets a tree whose help renders the same bytes wherever it runs, which is what a test and a completion script both need: main’s completions states paint::ColorMode::Plain, and tests/width.rs renders both modes and compares them.