### Question:
KeyStoreMaterialsProvider implements EncryptionMaterialsProvider { @Override public void refresh() { try { loadKeys(); } catch (GeneralSecurityException ex) { throw new DynamoDBMappingException("Unable to load keys from keystore", ex); } } KeyStoreMaterialsProvider(KeyStore keyStore, String encryptionAlias, String signingAlias, Map<String, String> description);  KeyStoreMaterialsProvider(KeyStore keyStore, String encryptionAlias, String signingAlias,
            ProtectionParameter encryptionProtection, ProtectionParameter signingProtection,
            Map<String, String> description); @Override DecryptionMaterials getDecryptionMaterials(EncryptionContext context); @Override EncryptionMaterials getEncryptionMaterials(EncryptionContext context); @Override void refresh();  }### Answer:
@Test public void testRefresh() throws Exception { KeyStoreMaterialsProvider prov = new KeyStoreMaterialsProvider(keyStore, "enc", "sig", passwordProtection, passwordProtection, description); prov.refresh(); }