pub fn apply(
scene: &mut Scene,
uses: &mut Uses,
edits: &Edits,
) -> Result<Applied, String>Expand description
Applies edits to scene, whose files uses counts, or says why it
can’t — leaving both as they were. The work is the edits’: each finds its
nodes by id, and the files no node uses any more are dropped by count,
never by a walk of the scene.