Function part_class 

pub fn part_class(part: Prominence) -> &'static str

The class for a row part, by how far forward it stands.

Prominence is #[non_exhaustive], so a member added upstream does not stop this compiling.

The fallback is what that costs. A member added upstream lands here as a bare row-part, which the sheet lets shrink like its siblings and otherwise leaves plain: a thing rendering plainly rather than a build that stops. Grep this function when adopting a new makeover-layout.

Public, because a row’s parts are emitted by whoever builds the row element and that is not always the same host: a table’s cells are one emitter, but a list row carries the app’s identity and hooks, so a screen renderer writes it. A renderer that reimplements this list rather than calling it takes on the obligation above without knowing it.