### Question:
SymmetricStaticProvider implements EncryptionMaterialsProvider { @Override public void refresh() { } SymmetricStaticProvider(SecretKey encryptionKey, KeyPair signingPair);  SymmetricStaticProvider(SecretKey encryptionKey,
            KeyPair signingPair, Map<String, String> description);  SymmetricStaticProvider(SecretKey encryptionKey, SecretKey macKey);  SymmetricStaticProvider(SecretKey encryptionKey, SecretKey macKey, Map<String, String> description); @Override DecryptionMaterials getDecryptionMaterials(EncryptionContext context); @Override EncryptionMaterials getEncryptionMaterials(EncryptionContext context); @Override void refresh();  }### Answer:
@Test public void testRefresh() { SymmetricStaticProvider prov = new SymmetricStaticProvider(encryptionKey, macKey, description); prov.refresh(); }