try {
      Hashing.hmacMd5(MD5_KEY);
      fail("expected ISE");
    } catch (IllegalStateException expected) {
    } finally {
      Providers.setProviderList(providers);
    }
  }

  public void testMultipleUpdates() throws Exception {
    Mac mac = Mac.getInstance("HmacSHA1");
    mac.init(SHA1_KEY);
    mac.update("hello".getBytes(UTF_8));
    mac.update("world".getBytes(UTF_8));

    assertEquals(