Invoker { public static <T> Optional<T> quietlyEval(String action, String path, Operation<T> operation) { try { return Optional.of(once(action, path, operation)); } catch (Exception e) { LOG.debug("Action {} failed", action, e); return Optional.empty(); } } Invoker(
      RetryPolicy retryPolicy,
      Retried retryCallback); RetryPolicy getRetryPolicy(); Retried getRetryCallback(); @Retries.OnceTranslated static T once(String action, String path, Operation<T> operation); @Retries.OnceTranslated static void once(String action, String path, VoidOperation operation); static void ignoreIOExceptions(
      Logger log,
      String action,
      String path,
      Operation<T> operation); static void ignoreIOExceptions(
      Logger log,
      String action,
      String path,
      VoidOperation operation); @Retries.RetryTranslated void retry(String action,
      String path,
      boolean idempotent,
      Retried retrying,
      VoidOperation operation); @Retries.RetryTranslated void retry(String action,
      String path,
      boolean idempotent,
      VoidOperation operation); @Retries.RetryTranslated T retry(String action,
      @Nullable String path,
      boolean idempotent,
      Operation<T> operation); @Retries.RetryTranslated T retry(
      String action,
      @Nullable String path,
      boolean idempotent,
      Retried retrying,
      Operation<T> operation); @Retries.RetryRaw T retryUntranslated(
      String text,
      boolean idempotent,
      Operation<T> operation); @Retries.RetryRaw T retryUntranslated(
      String text,
      boolean idempotent,
      Retried retrying,
      Operation<T> operation); static void quietly(String action,
      String path,
      VoidOperation operation); static Optional<T> quietlyEval(String action,
      String path,
      Operation<T> operation); static final Retried NO_OP; static final Retried LOG_EVENT; }
@Test public void testQuietlyVoid() { quietlyEval("", "", () -> { throw HADOOP_CONNECTION_TIMEOUT_EX; }); }
@Test public void testQuietlyEvalReturnValueSuccess() { assertOptionalEquals("quietly", 3, quietlyEval("", "", () -> 3)); }
@Test public void testQuietlyEvalReturnValueFail() { int d = 0; assertOptionalUnset("quietly", quietlyEval("", "", () -> 3 / d)); }