CountingRunnable after = new CountingRunnable();

    future.addListener(before, directExecutor());
    future.setFuture(delegate);
    future.addListener(inBetween, directExecutor());
    delegate.set(1);
    future.addListener(after, directExecutor());

    before.assertRun();
    inBetween.assertRun();
    after.assertRun();
  }

   */
  public MapJoiner withKeyValueSeparator(String keyValueSeparator) {
    return new MapJoiner(this, keyValueSeparator);
  }

  /**
   * An object that joins map entries in the same manner as {@code Joiner} joins iterables and
   * arrays. Like {@code Joiner}, it is thread-safe and immutable.
   *
   * <p>In addition to operating on {@code Map} instances, {@code MapJoiner} can operate on {@code

      fail("putIfAbsent(null, value) should throw");
    } catch (NullPointerException expected) {
    }
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupported() {
    try {

    assertEquals(
        "multiset.remove(present, 2) didn't return the old count",
        1,
        getMultiset().remove(e0(), 2));
    assertFalse(
        "multiset contains present after multiset.remove(present, 2)",
        getMultiset().contains(e0()));
    assertEquals(0, getMultiset().count(e0()));
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)

    assertEquals(
        "multiset.remove(present, 2) didn't return the old count",
        1,
        getMultiset().remove(e0(), 2));
    assertFalse(
        "multiset contains present after multiset.remove(present, 2)",
        getMultiset().contains(e0()));
    assertEquals(0, getMultiset().count(e0()));
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)

   *     operation
   */
  void add(Range<C> range);

  /**
   * Removes the specified range from this {@code RangeSet} (optional operation). After this
   * operation, if {@code range.contains(c)}, {@code this.contains(c)} will return {@code false}.
   *
   * <p>If {@code range} is empty, this is a no-op.
   *

          + ")";
    }
  }

  /**
   * Returns a supplier that caches the instance supplied by the delegate and removes the cached
   * value after the specified time has passed. Subsequent calls to {@code get()} return the cached
   * value if the expiration time has not passed. After the expiration time, a new value is
   * retrieved, cached, and returned. See: <a
   * href="http://en.wikipedia.org/wiki/Memoization">memoization</a>
   *

  public boolean isEmpty() {
    return map.isEmpty();
  }

  /**
   * Removes all of the mappings from this map. The map will be empty after this call returns.
   *
   * <p>This method is not atomic: the map may not be empty after returning if there were concurrent
   * writes.
   */
  public void clear() {
    map.clear();
  }

  @Override
  public String toString() {

        // The trickled element is still after index.
        return new MoveDesc<>(actualLastElement, toTrickle);
      } else {
        // The trickled element is back before index, but the replaced element
        // has now been moved after index.
        return new MoveDesc<>(actualLastElement, changes.replaced);
      }
    }
    // Trickled element was after index to begin with, no adjustment needed.

    }
  }

  /**
   * Quickselects the top k elements from the 2k elements in the buffer. O(k) expected time, O(k log
   * k) worst case.
   */
  @SuppressWarnings("nullness") // TODO: b/316358623 - Remove after checker fix.
  private void trim() {
    int left = 0;
    int right = 2 * k - 1;

    int minThresholdPosition = 0;
    // The leftmost position at which the greatest of the k lower elements