Function insert 

fn insert(
    indexed: &IndexedDocument<'_>,
    insertion: Insertion<'_>,
    naming: Naming<'_>,
    boundary: Boundary<'_>,
    builder: &mut CommitBuilder,
) -> Vec<Shape>

One paste, both halves (Naming): every entity re-created at its landing, the roots re-pointed at the target scope and shifted by the drop.