assertNodeDoesNotExist example

'title' => 'Item 3 updated',
        'changed' => 4,
      ])
      ->condition('title', 'Item 3')
      ->execute();

    // Execute migration again.     $this->executeMigration('high_water_test');

    // Item with lower high water should not be updated.     $this->assertNodeExists('Item 1');
    $this->assertNodeDoesNotExist('Item 1 updated');

    // Item with equal high water should not be updated.     $this->assertNodeExists('Item 2');
    $this->assertNodeDoesNotExist('Item 2 updated');

    // Item with greater high water should be updated.     $this->assertNodeExists('Item 3 updated');
    $this->assertNodeDoesNotExist('Item 3');
  }

  /** * Tests that the high water value can be 0. */