@CheckForNull Executor nextExecutor;
  }

  /**
   * Enqueues a task to run when the previous task (if any) completes.
   *
   * <p>Cancellation does not propagate from the output future to a callable that has begun to
   * execute, but if the output future is cancelled before {@link Callable#call()} is invoked,
   * {@link Callable#call()} will not be invoked.
   */
  public <T extends @Nullable Object> ListenableFuture<T> submit(

    @Override
    protected void implCloseChannel() {
      throw new RuntimeException("I bet you didn't think Thread.interrupt could throw");
    }

    void doBegin() {
      super.begin();
    }
  }

  /**
   * Because Thread.interrupt() can invoke arbitrary code, it can be slow (e.g. perform IO). To
   * protect ourselves from that we want to make sure that tasks don't spin too much waiting for the

     * the number of entries in the map, as that makes it easy for hostile inputs to trigger lots of
     * allocation—not that any program should be deserializing hostile inputs to begin with!)
     */
    setDelegates(new EnumMap<K, V>(keyTypeOrObjectUnderJ2cl), new HashMap<V, K>());
    Serialization.populateMap(this, stream);
  }

  @GwtIncompatible // only needed in emulated source.

    }
  }

  /**
   * Removes a number of occurrences of the specified element from this multiset. If the multiset
   * contains fewer than this number of occurrences to begin with, all occurrences will be removed.
   *
   * @param element the element whose occurrences should be removed
   * @param occurrences the number of occurrences of the element to remove

            "42.42.42.ab",
            "3ffe::1.net",
            "3ffe::1::1",
            "1::2::3::4:5",
            "::7:6:5:4:3:2:", // should end with ":0"
            ":6:5:4:3:2:1::", // should begin with "0:"
            "2001::db:::1",
            "FEDC:9878",
            "+1.+2.+3.4",
            "1.2.3.4e0",
            "6:5:4:3:2:1:0", // too few parts
            "::7:6:5:4:3:2:1:0", // too many parts

      return false;
    }

    /*
     * Note that we allow (in contravention of a strict interpretation of the relevant RFCs) domain
     * parts other than the last may begin with a digit (for example, "3com.com"). It's important to
     * disallow an initial digit in the last part; it's the only thing that stops an IPv4 numeric
     * address like 127.0.0.1 from looking like a valid domain name.

    @Override
    protected void implCloseChannel() {
      throw new RuntimeException("I bet you didn't think Thread.interrupt could throw");
    }

    void doBegin() {
      super.begin();
    }
  }

  /**
   * Because Thread.interrupt() can invoke arbitrary code, it can be slow (e.g. perform IO). To
   * protect ourselves from that we want to make sure that tasks don't spin too much waiting for the

    // Note: assert<b>Same</b> for this implementation.
    String s = "blah blah farhvergnugen";
    assertSame(s, htmlEscaper().escape(s));

    // Tests escapes at begin and end of string.
    assertEquals("&lt;p&gt;", htmlEscaper().escape("<p>"));

    // Test all escapes.
    assertEquals("a&quot;b&lt;c&gt;d&amp;", htmlEscaper().escape("a\"b<c>d&"));

    // Test two escapes in a row.

                  }
                });

    // To start, fill up the cache.
    // Each miss both increments the counter and causes the map to grow by one,
    // so until evictions begin, the size of the map is the greatest return
    // value seen so far
    while (cache.getUnchecked(nextRandomKey()) < maximumSize) {}

    requests.set(0);
    misses.set(0);
  }

  @Benchmark

 * <h4>Automatically closing</h4>
 *
 * You can extract a {@link Future} that represents the result of the last step in the pipeline by
 * calling {@link #finishToFuture()}. All objects the pipeline has captured for closing will begin
 * to be closed asynchronously <b>after</b> the returned {@code Future} is done: the future
 * completes before closing starts, rather than once it has finished.
 *
 * <pre>{@code
 * FluentFuture<UserName> userName =