storageLayerID identifies a compartment within a storage unit or equipment (a shelf, rack, box, or similar). Every storage unit also has a root compartment whose storageLayerID is returned by GET /storage/{storageID}.

To retrieve the parent storage unit's `storageID` from a known `storageLayerID`, use `?$expand=storage` — the parent's `storageID` is then available as `storage.storageID` on the response.

$expand values (separate with a comma for multiple expands):
* storage
* location
* storageLayers
* samples
* managers
* reservations / allReservations
* activeReservation
* activeValidation
* statistics

Note: if you use the expand `storageLayers` and `statistics` simultaneously then statistics will also be added for the child storage layers.