}

    @Test
    public void test_offer_and_drainAll() {
        LogNotificationHelper helper = new LogNotificationHelper();
        helper.offer(new LogNotificationEvent(1000L, "ERROR", "com.example.Foo", "message1", "throwable1"));
        helper.offer(new LogNotificationEvent(2000L, "WARN", "com.example.Bar", "message2", null));

        List<LogNotificationEvent> events = helper.drainAll();
        assertEquals(2, events.size());

import static com.google.common.base.Throwables.getCausalChain;
import static com.google.common.base.Throwables.getCauseAs;
import static com.google.common.base.Throwables.getRootCause;
import static com.google.common.base.Throwables.getStackTraceAsString;
import static com.google.common.base.Throwables.lazyStackTrace;
import static com.google.common.base.Throwables.lazyStackTraceIsLazy;

    @Override
    public void suppress(Closeable closeable, Throwable thrown, Throwable suppressed) {
      suppressions.add(new Suppression(closeable, thrown, suppressed));
    }
  }

  /** Record of a call to suppress. */
  private static class Suppression {
    private final Closeable closeable;
    private final Throwable thrown;
    private final Throwable suppressed;

    @Override
    public void suppress(Closeable closeable, Throwable thrown, Throwable suppressed) {
      suppressions.add(new Suppression(closeable, thrown, suppressed));
    }
  }

  /** Record of a call to suppress. */
  private static class Suppression {
    private final Closeable closeable;
    private final Throwable thrown;
    private final Throwable suppressed;

    Throwable throwable = thrown;

    // close closeables in LIFO order
    while (!stack.isEmpty()) {
      Closeable closeable = stack.removeFirst();
      try {
        closeable.close();
      } catch (Throwable e) {
        if (throwable == null) {
          throwable = e;
        } else {
          suppressor.suppress(closeable, throwable, e);
        }
      }
    }

      } catch (InterruptedException e) {
        // ignore
      }
    }
  }

  /**
   * Cleans up the given reference and any other references already in the queue. Catches and logs
   * all throwables.
   *
   * @return true if the caller should continue to wait for more references to be added to the
   *     queue, false if the associated FinalizableReferenceQueue is no longer referenced.
   */

    /** List of errors. */
    protected final List<Throwable> errors = new ArrayList<>();
    /** Time taken for the operation in milliseconds. */
    protected final long took;

    /**
     * Constructor for SuggestIndexResponse.
     * @param numberOfSuggestDocs The number of suggest documents.
     * @param numberOfInputDocs The number of input documents.
     * @param errors A list of Throwables representing errors.

      } catch (InterruptedException e) {
        // ignore
      }
    }
  }

  /**
   * Cleans up the given reference and any other references already in the queue. Catches and logs
   * all throwables.
   *
   * @return true if the caller should continue to wait for more references to be added to the
   *     queue, false if the associated FinalizableReferenceQueue is no longer referenced.
   */

        catchingAsync(failingFuture, Throwable.class, fallback, directExecutor());
    assertEquals(20, getDone(faultTolerantFuture).intValue());
    fallback.verifyCallCount(1);
  }

  @J2ktIncompatible
  @GwtIncompatible // non-Throwable exceptionType
  public void testCatchingAsync_inputCancelledWithoutFallback() throws Exception {
    AsyncFunction<Throwable, Integer> fallback = unexpectedAsyncFunction();

        catchingAsync(failingFuture, Throwable.class, fallback, directExecutor());
    assertEquals(20, getDone(faultTolerantFuture).intValue());
    fallback.verifyCallCount(1);
  }

  @J2ktIncompatible
  @GwtIncompatible // non-Throwable exceptionType
  public void testCatchingAsync_inputCancelledWithoutFallback() throws Exception {
    AsyncFunction<Throwable, Integer> fallback = unexpectedAsyncFunction();