public function orphaned($master, array $processIds)
    {
        $time = Chronos::now()->getTimestamp();

        $shouldRemove = array_diff($this->connection()->hkeys(
            $key = "{$master}:orphans"
        ), $processIds);

        if (! empty($shouldRemove)) {
            $this->connection()->hdel($key, ...$shouldRemove);
        }

        $this->connection()->pipeline(function ($pipe) use ($key, $time, $processIds) {
            foreach ($processIds as $processId) {
                $pipe->hsetnx($key, $processId, $time);
            }
        });
    }