public function testRegister()
{
// New instance so we have an empty register.
$indicesManager = new IndicesManager($this->getElasticSearcher());
$moviesIndex = new MoviesIndex();
// Single registration.
$indicesManager->register($moviesIndex);
$this->assertEquals(true, $indicesManager->isRegistered('movies'));
$this->assertArrayHasKey('movies', $indicesManager->registeredIndices());
$this->assertInstanceOf(MoviesIndex::class, $indicesManager->getRegistered('movies'));
// Removing from register.
$indicesManager->unregister('movies');
$this->assertEquals(false, $indicesManager->isRegistered('movies'));
$this->assertArrayNotHasKey('movies', $indicesManager->registeredIndices());
// Bulk registering.
$indicesManager->registerIndices([$moviesIndex]);
$this->assertEquals(true, $indicesManager->isRegistered('movies'));
}