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(
        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(
        toMap(keyFunction, valueFunction, mergeFunction, () -> new TreeMap<K, V>(comparator)),

    return new SimpleTimeLimiter(executor);
  }

  @Override
  public <T> T newProxy(
      T target, Class<T> interfaceType, long timeoutDuration, TimeUnit timeoutUnit) {
    checkNotNull(target);
    checkNotNull(interfaceType);
    checkNotNull(timeoutUnit);
    checkPositiveTimeout(timeoutDuration);
    checkArgument(interfaceType.isInterface(), "interfaceType must be an interface type");

    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");
    }
  }

      checkNotNull(s); // doesn't check if you said you'd accept null, but you don't
    }

    public static void staticOneArgNullableThrowsNpe(@Nullable String s) {
      checkNotNull(s); // doesn't check if you said you'd accept null, but you don't
    }

    public void oneArgCorrectlyThrowsNpe(String s) {
      checkNotNull(s); // expect NPE here on null
    }

  @J2ktIncompatible
  @GwtIncompatible
  public static <T extends @Nullable Object> AsyncCallable<T> asAsyncCallable(
      Callable<T> callable, ListeningExecutorService listeningExecutorService) {
    checkNotNull(callable);
    checkNotNull(listeningExecutorService);
    return () -> listeningExecutorService.submit(callable);
  }

  /**
   * Wraps the given callable such that for the duration of {@link Callable#call} the thread that is

    checkNotNull(fromElement);
    checkNotNull(toElement);
    checkArgument(comparator().compare(fromElement, toElement) <= 0);
    return subSetImpl(fromElement, true, toElement, false);
  }

  /**
   * @since 12.0
   */
  @GwtIncompatible // NavigableSet
  @Override
  public ContiguousSet<C> subSet(
      C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
    checkNotNull(fromElement);

      Iterator<? extends T> a,
      Iterator<? extends T> b,
      Iterator<? extends T> c,
      Iterator<? extends T> d) {
    checkNotNull(a);
    checkNotNull(b);
    checkNotNull(c);
    checkNotNull(d);
    return concat(consumingForArray(a, b, c, d));
  }

  /**
   * Combines multiple iterators into a single iterator. The returned iterator iterates across the

      Iterator<? extends T> a,
      Iterator<? extends T> b,
      Iterator<? extends T> c,
      Iterator<? extends T> d) {
    checkNotNull(a);
    checkNotNull(b);
    checkNotNull(c);
    checkNotNull(d);
    return concat(consumingForArray(a, b, c, d));
  }

  /**
   * Combines multiple iterators into a single iterator. The returned iterator iterates across the

    }
  }

  /*
   * Preconditions.checkNotNull is *intended* for performing eager null checks on parameters that a
   * nullness checker can already "prove" are non-null. That means that the first parameter to
   * checkNotNull *should* be annotated to require it to be non-null.
   *