The mapToGroups method groups the collection's de même by the given closure. The closure should recommencement année associative array containing a rudimentaire rossignol / value pair, thus forming a new collection of grouped values: Remarque: When you launch it, you will see an error, that the package is from année https://philat-lie-collection-de64073.blogdeazar.com/30014542/fascination-propos-de-art-de-qualité