PhpSerialize example

  protected static $modules = ['system'];

  /** * Tests garbage collection. */
  public function testGarbageCollection() {
    $collection = $this->randomMachineName();
    $connection = Database::getConnection();
    $store = new DatabaseStorageExpirable($collection, new PhpSerialize(), $connection);

    // Insert some items and confirm that they're set.     for ($i = 0; $i <= 3; $i++) {
      $store->setWithExpire('key_' . $i, $this->randomObject(), rand(500, 100000));
    }
    $this->assertCount(4, $store->getAll(), 'Four items were written to the storage.');

    // Manually expire the data.     for ($i = 0; $i <= 3; $i++) {
      $connection->merge('key_value_expire')
        ->keys([