How to run a cron queue programmatically? I have created a cron queue like given below.

function mymodule_cron_queue_info() {
  $queues['aggregator_feeds'] = array(
    'worker callback' =&gt; 'aggregator_refresh',
    'time' =&gt; 60,
  );
  return $queues;
}


My cron runs when calling drush cron. I need to run the queue 'aggregator_feeds' individually without invoking any other cron queues. Drupal admin panel -> config -> cron : runs all queues as per schedule. 
drush cron command too runs all queue. How do I run a single queue programmatically?

Also I need to know how to run all the queues programmatically?
For one of my project, this worked for me :-

$queue_machine_name = 'sync_product_list';
$queue = \Drupal::queue($queue_machine_name); 
$queue_worker = \Drupal::service('plugin.manager.queue_worker')-&gt;createInstance($queue_machine_name);
$item_id = '123';
$queue_worker-&gt;processItem($item_id);