Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction,
          BinaryOperator<V> mergeFunction) {
    checkNotNull(comparator);
    checkNotNull(keyFunction);
    checkNotNull(valueFunction);
    checkNotNull(mergeFunction);
    return collectingAndThen(
        Collectors.toMap(
            keyFunction, valueFunction, mergeFunction, () -> new TreeMap<K, V>(comparator)),

          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction,
          BinaryOperator<V> mergeFunction) {
    checkNotNull(comparator);
    checkNotNull(keyFunction);
    checkNotNull(valueFunction);
    checkNotNull(mergeFunction);
    return collectingAndThen(
        Collectors.toMap(
            keyFunction, valueFunction, mergeFunction, () -> new TreeMap<K, V>(comparator)),

        return new String(factoryExpectedForNothing, Charsets.UTF_8) + checkNotNull(data);
      }

      @Override
      public void tearDown() throws IOException {
        factory.tearDown();
      }
    };
  }

  public static ByteSourceFactory asSlicedByteSourceFactory(
      final ByteSourceFactory factory, final long off, final long len) {
    checkNotNull(factory);
    return new ByteSourceFactory() {
      @Override

  public void callAndAssertThrows(
      Class<? extends Throwable> expected, String methodName, Object... arguments)
      throws Exception {
    checkNotNull(expected);
    checkNotNull(methodName);
    checkNotNull(arguments);
    sendRequest(methodName, arguments);
    assertEquals(expected, getResponse(methodName).getThrowable().getClass());
  }

  /**

  public void callAndAssertThrows(
      Class<? extends Throwable> expected, String methodName, Object... arguments)
      throws Exception {
    checkNotNull(expected);
    checkNotNull(methodName);
    checkNotNull(arguments);
    sendRequest(methodName, arguments);
    assertEquals(expected, getResponse(methodName).getThrowable().getClass());
  }

  /**

    public void twoArg(String s, Integer i) {
      checkNotNull(s);
      i.intValue();
    }

    public void twoMixedArgs(String s, @Nullable Integer i) {
      checkNotNull(s);
    }

    public void twoMixedArgs(@Nullable Integer i, String s) {
      checkNotNull(s);
    }

    public void twoMixedArgsThrows(String s, @Nullable Integer i) {
      checkNotNull(s);
      doThrow(i);
    }

    public InstantiableFactoryMethodChosen(NotInstantiable x) {
      checkNotNull(x);
      this.name = "x1";
    }

    public static InstantiableFactoryMethodChosen create(NotInstantiable x) {
      return new InstantiableFactoryMethodChosen(x);
    }

    public static InstantiableFactoryMethodChosen create(String s) {
      checkNotNull(s);
      return new InstantiableFactoryMethodChosen("good");
    }
  }

    return headSetImpl(checkNotNull(toElement), false);
  }

  /** @since 12.0 */
  @GwtIncompatible // NavigableSet
  @Override
  public ContiguousSet<C> headSet(C toElement, boolean inclusive) {
    return headSetImpl(checkNotNull(toElement), inclusive);
  }

  @Override
  public ContiguousSet<C> subSet(C fromElement, C toElement) {
    checkNotNull(fromElement);
    checkNotNull(toElement);

      Comparator<? super E> comparator, E... elements) {
    checkNotNull(elements);
    switch (elements.length) {
      case 0:
        return emptySet(comparator);
      default:
        SortedSet<E> delegate = new TreeSet<E>(comparator);
        for (E element : elements) {
          checkNotNull(element);
          delegate.add(element);
        }

        return copyReaderToBuilder((Reader) from, (StringBuilder) to);
      } else {
        return copyReaderToWriter((Reader) from, asWriter(to));
      }
    }

    checkNotNull(from);
    checkNotNull(to);
    long total = 0;
    CharBuffer buf = createBuffer();
    while (from.read(buf) != -1) {
      Java8Compatibility.flip(buf);
      to.append(buf);
      total += buf.remaining();