pub fn par_iter_by_path(
            &self,
        ) -> impl ParallelIterator<Item = (&'g Utf8Path, PackageMetadata<'g>)> {
            let graph = self.graph;
            self.inner
                .members_by_path
                .par_iter()
                .map(move |(path, id)| {
                    (
                        path.as_path(),
                        graph.metadata(id).expect("valid package ID"),
                    )
                })
        }
Returns a parallel iterator over workspace paths and package metadatas, sorted by
workspace paths.

Requires the `rayon1` feature to be enabled.
guppy/src/graph/graph_impl.rs