assertRevisionCount example

$page = $this->getSession()->getPage();
    $page->fillField('Name', 'Foobar');
    $page->attachFileToField('File', $this->container->get('file_system')->realpath($uri));
    $page->pressButton('Save');
    $assert->addressEquals('admin/content/media');

    // The media item was just created, so it should only have one revision.     $media = $this->container
      ->get('entity_type.manager')
      ->getStorage('media')
      ->load(1);
    $this->assertRevisionCount($media, 1);

    // If we edit the item, we should get a new revision.     $this->drupalGet('/media/1/edit');
    $assert->checkboxChecked('Create new revision');
    $page = $this->getSession()->getPage();
    $page->fillField('Name', 'Foo');
    $page->pressButton('Save');
    $this->assertRevisionCount($media, 2);

    // Confirm the correct revision title appears on "view revisions" page.     $media = $this->container->get('entity_type.manager')