code: private function pop(array &$list, $oid, StockUnitInterface $unit)
      {
          if (false !== $index = $this->find($list, $oid, $unit)) {
              unset($list[$oid][$index]);
  
              if (empty($list[$oid])) {
                  unset($list[$oid]);
              }
          }
      }
docs: Pops the unit to the given list for the given object identifier.
  
  @param array              $list
  @param string             $oid
  @param StockUnitInterface $unit