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