### Question:
ALSServingModelManager extends AbstractServingModelManager<String> { static RescorerProvider loadRescorerProviders(String classNamesString) { if (classNamesString == null || classNamesString.isEmpty()) { return null; } String[] classNames = classNamesString.split(","); if (classNames.length == 1) { return loadInstanceOf(classNames[0]); } RescorerProvider[] providers = new RescorerProvider[classNames.length]; for (int i = 0; i < classNames.length; i++) { providers[i] = loadInstanceOf(classNames[i]); } return MultiRescorerProvider.of(providers); } ALSServingModelManager(Config config); @Override void consumeKeyMessage(String key, String message, Configuration hadoopConf); @Override ALSServingModel getModel();  }### Answer:
@Test public void testLoad() { assertNull(ALSServingModelManager.loadRescorerProviders(null)); RescorerProvider provider = ALSServingModelManager.loadRescorerProviders( "com.cloudera.oryx.app.serving.als.model.NullProvider2"); assertInstanceOf(provider, NullProvider2.class); RescorerProvider multiProvider = ALSServingModelManager.loadRescorerProviders( "com.cloudera.oryx.app.serving.als.model.NullProvider2," + "com.cloudera.oryx.app.serving.als.model.NullProvider2"); assertInstanceOf(multiProvider, MultiRescorerProvider.class); }
@Test(expected = IllegalArgumentException.class) public void testNoClass() { ALSServingModelManager.loadRescorerProviders("noSuchClass"); }
@Test(expected = IllegalArgumentException.class) public void testBadInstantiation() { ALSServingModelManager.loadRescorerProviders("com.cloudera.oryx.app.als.ErrorProvider"); }
@Test(expected = IllegalArgumentException.class) public void testWrongClass() { ALSServingModelManager.loadRescorerProviders( "com.cloudera.oryx.app.als.AbstractRescorerProviderTest"); }