removeEntityIndex example

    $this->assertEquals($expected, $this->entityDefinitionUpdateManager->getChangeSummary(), 'EntityDefinitionUpdateManager reports the expected change summary.');

    // Run the update and ensure the new index is created.     $entity_type = \Drupal::entityTypeManager()->getDefinition('entity_test_update');
    $original = \Drupal::service('entity.last_installed_schema.repository')->getLastInstalledDefinition('entity_test_update');
    \Drupal::service('entity_type.listener')->onEntityTypeUpdate($entity_type, $original);
    $this->assertTrue($this->database->schema()->indexExists('entity_test_update', 'entity_test_update__new_index'), 'Index created.');

    // Remove the index and ensure the update manager reports that as an     // update to the entity type.     $this->removeEntityIndex();
    $this->assertTrue($this->entityDefinitionUpdateManager->needsUpdates(), 'EntityDefinitionUpdateManager reports that updates are needed.');
    $expected = [
      'entity_test_update' => [
        t('The %entity_type entity type needs to be updated.', ['%entity_type' => $this->entityTypeManager->getDefinition('entity_test_update')->getLabel()]),
      ],
    ];
    $this->assertEquals($expected, $this->entityDefinitionUpdateManager->getChangeSummary(), 'EntityDefinitionUpdateManager reports the expected change summary.');

    // Run the update and ensure the index is deleted.     $entity_type = \Drupal::entityTypeManager()->getDefinition('entity_test_update');
    $original = \Drupal::service('entity.last_installed_schema.repository')->getLastInstalledDefinition('entity_test_update');