If anything, it’s less clear to me… :P Examine this for a moment before you update or try to clarify–

perl -MData::Dump=pp -e "pp {aaa=>'bbb', bbb=>'aaa', ccc=>'bbb', bbb=>
+'ccc', abc=>'123'}"
{ aaa => "bbb", abc => 123, bbb => "ccc", ccc => "bbb" }
[download]

Maybe hashes don’t work the way you think? You see the extra bbb key is already “deduplicated.”

Update: and you silently updated the code in the OP… again. :(