Function collect_reverse_contributions 

pub fn collect_reverse_contributions<'a>(
    importer: &'a Module,
    alias: &str,
    imported: &'a Module,
) -> ReverseContributions

Collect the contributions importer makes to imported through the given use alias. Only qualified references using alias are considered, so an unrelated co-supplied file contributes nothing. Statuses and transitions are filtered to values imported actually declares.