Sets up unit test environment.
Unlike Drupal\simpletest\WebTestBase::setUp(), UnitTestBase::setUp() does not install modules because tests are performed without accessing the database. Any required files must be explicitly included by the child class setUp() method.
Overrides StorageTestBase::setUp
protected function setUp() {
parent::setUp();
$this->container
->register('keyvalue.memory', 'Drupal\\Core\\KeyValueStore\\KeyValueMemoryFactory');
global $conf;
if (isset($conf['keyvalue_default'])) {
$this->originalKeyValue = $conf['keyvalue_default'];
}
$conf['keyvalue_default'] = 'keyvalue.memory';
}