### Question:
DirectKmsMaterialsProvider implements EncryptionMaterialsProvider { @Override public void refresh() { } DirectKmsMaterialsProvider(KmsClient kms);  DirectKmsMaterialsProvider(KmsClient kms, String encryptionKeyId, Map<String, String> materialDescription);  DirectKmsMaterialsProvider(KmsClient kms, String encryptionKeyId); @Override DecryptionMaterials getDecryptionMaterials(EncryptionContext context); @Override EncryptionMaterials getEncryptionMaterials(EncryptionContext context); @Override void refresh();  }### Answer:
@Test public void testRefresh() { DirectKmsMaterialsProvider prov = new DirectKmsMaterialsProvider(kms, keyId); prov.refresh(); }