6 string references to queue in Drupal 9

BatchBuilderTest::testDefaultValues in core/tests/Drupal/Tests/Core/Batch/BatchBuilderTest.php

Tests the default values.

CronQueueTest::setUp in core/modules/system/tests/src/Kernel/System/CronQueueTest.php

CronQueueTest::testDelayException in core/modules/system/tests/src/Kernel/System/CronQueueTest.php

Tests that DelayedRequeueException behaves as expected when running cron.

drupal7.php in core/modules/migrate_drupal/tests/fixtures/drupal7.php

A database agnostic dump for testing purposes.

DrupalTest::testQueue in core/tests/Drupal/Tests/Core/DrupalTest.php

Tests the queue() method.

system_cron in core/modules/system/system.module

Implements hook_cron().