### Question:
RangerCredentialProvider { List<CredentialProvider> getCredentialProviders(String url){ try { Configuration conf = new Configuration(); conf.set(CredentialProviderFactory.CREDENTIAL_PROVIDER_PATH, url); return CredentialProviderFactory.getProviders(conf); } catch(Exception ie) { LOG.error("Unable to get the Credential Provider from the Configuration", ie); } return null; }  static RangerCredentialProvider getInstance(); char[] getCredentialString(String url, String alias);  }### Answer:
@Test public void testCredentialProvider() { cp = new RangerCredentialProvider(); providers = cp.getCredentialProviders(url); if (providers != null) { assertTrue(url.equals(providers.get(0).toString())); } System.out.println("(2) Number of active Threads : " + Thread.activeCount() ) ; listThreads() ; }