Function window_language 

pub fn window_language(shipped: &[&str]) -> String

The language a window speaks, chosen once from the person’s preference and the languages what the window shows ships (shipped, the locales of its catalogues): the language they prefer when it is among them, the same language in another region when that is, the source language when it ships that, else the first it ships. One window speaks one language, so an app that ships a translation leaves none of its chrome, its frames’ words or its dates in another. See [tilo_history::window_language].