new OutputStream() {
        /** Discards the specified byte. */
        @Override
        public void write(int b) {}

        /** Discards the specified byte array. */
        @Override
        public void write(byte[] b) {
          checkNotNull(b);
        }

        /** Discards the specified byte array. */
        @Override

  /** Discards any cached value for key {@code key}. */
  void invalidate(@CompatibleWith("K") Object key);

  /**
   * Discards any cached values for keys {@code keys}.
   *
   * @since 11.0
   */
  // For discussion of <? extends Object>, see getAllPresent.
  void invalidateAll(Iterable<? extends Object> keys);

  /** Discards all entries in the cache. */
  void invalidateAll();

  @Override
  void writeDouble(double v);

  @Override
  void writeChars(String s);

  @Override
  void writeUTF(String s);

  /**
   * @deprecated This method is dangerous as it discards the high byte of every character. For
   *     UTF-8, use {@code write(s.getBytes(StandardCharsets.UTF_8))}.
   */
  @Deprecated
  @Override
  void writeBytes(String s);

   *
   * <p>Prefer this method instead of manually casting an exception's cause. For example, {@code
   * (IOException) e.getCause()} throws a {@link ClassCastException} that discards the original
   * exception {@code e} if the cause is not an {@link IOException}, but {@code
   * Throwables.getCauseAs(e, IOException.class)} keeps {@code e} as the {@link
   * ClassCastException}'s cause.
   *

   *
   * <p>Prefer this method instead of manually casting an exception's cause. For example, {@code
   * (IOException) e.getCause()} throws a {@link ClassCastException} that discards the original
   * exception {@code e} if the cause is not an {@link IOException}, but {@code
   * Throwables.getCauseAs(e, IOException.class)} keeps {@code e} as the {@link
   * ClassCastException}'s cause.
   *

  /** Discards any cached value for key {@code key}. */
  void invalidate(@CompatibleWith("K") Object key);

  /**
   * Discards any cached values for keys {@code keys}.
   *
   * @since 11.0
   */
  // For discussion of <? extends Object>, see getAllPresent.
  void invalidateAll(Iterable<? extends Object> keys);

  /** Discards all entries in the cache. */
  void invalidateAll();

    }

    public void test_beginWithRecordAndDiscard() {
        String key = "test";
        crawlerStatsHelper.begin(key);
        crawlerStatsHelper.record(key, "aaa");
        crawlerStatsHelper.discard(key);
        logger.info(localLogMsg.get());
        assertNull(localLogMsg.get());

        crawlerStatsHelper.done(key);
        logger.info(localLogMsg.get());
        assertNull(localLogMsg.get());

          return 0;
        }

        @Override
        public Iterator<Object> iterator() {
          return ImmutableSet.of().iterator();
        }
      };

  /** Queue that discards all elements. */
  @SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
  static <E> Queue<E> discardingQueue() {
    return (Queue) DISCARDING_QUEUE;
  }

  /*

     * repository. It is worth to point out that merging does not simply choose one of the input repositories and
     * discards the others but actually combines their possibly different policies.
     *
     * @param repositories The original repositories, may be {@code null}.

          return 0;
        }

        @Override
        public Iterator<Object> iterator() {
          return ImmutableSet.of().iterator();
        }
      };

  /** Queue that discards all elements. */
  @SuppressWarnings("unchecked") // impl never uses a parameter or returns any non-null value
  static <E> Queue<E> discardingQueue() {
    return (Queue) DISCARDING_QUEUE;
  }

  /*