Function all_merged_tree_entries 

pub fn all_merged_tree_entries(
    trees: &Merge<Tree>,
) -> impl Iterator<Item = (&RepoPathComponent, MergedTreeVal<'_>)>

Suppose the given trees aren’t resolved, iterates (name, values) pairs non-recursively. This also works if trees are resolved, but is more costly than tree.entries_non_recursive().