The assembly comprises {TAIL ~ a plurality} of first slotted partitions intersecting with a plurality of second slotted partitions to form {HEAD ~ a collapsible matrix} 
The assembly comprises { TAIL ~ a plurality } of first slotted partitions intersecting with a plurality of second slotted partitions to form { HEAD ~ a collapsible matrix }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD