protected function applyOrderColumn($column, $orderable)
    {
        $sql      = $this->columnDef['order'][$column]['sql'];
        $sql      = str_replace('$1', $orderable['direction'], $sql);
        $bindings = $this->columnDef['order'][$column]['bindings'];
        $this->query->orderByRaw($sql, $bindings);
    }