BackdropWebTestCaseCache::tearDown in modules/simpletest/backdrop_web_test_case_cache.php

Reset the database prefix and global config.

BackdropWebTestCase::tearDown in modules/simpletest/backdrop_web_test_case.php

Delete created files and temporary files directory, delete the tables created by setUp(), and reset the database prefix.

LocaleLanguageNegotiationInfoFunctionalTest::languageNegotiationUpdate in modules/locale/tests/locale.test

Update language types/negotiation information.

module_disable in includes/module.inc

Disables a given set of modules.

module_enable in includes/module.inc

Enables or installs a given list of modules.

system_install in modules/system/system.install

Implements hook_install().

update.php in ./update.php

Administrative page for handling updates from one Backdrop version to another.

UpgradePathTestCase::performUpgrade in modules/simpletest/tests/upgrade/upgrade.test

Perform the upgrade.