protected function _getHighestOrder(array $scope = [])
    {
        $orderField = $this->_config['order'];

        // Find the last record in the set
        $last = $this->_table->find()
            ->select([$orderField])
            ->where($scope)
            ->order([$orderField => 'DESC'])
            ->limit(1)
            ->enableHydration(false)
            ->first();

        // If there is a last record (i.e. any) in the set, return the it's order
        if ($last) {
            return $last[$orderField];
        }

        // If there isn't any records in the set, return the start number minus 1
        return (int)$this->_config['start'] - 1;
    }