*   throwIfUnchecked(failure);
   *   throw new AssertionError(failure);
   * }
   * </pre>
   *
   * @since 20.0
   */
  public static void throwIfUnchecked(Throwable throwable) {
    checkNotNull(throwable);
    if (throwable instanceof RuntimeException) {
      throw (RuntimeException) throwable;
    }
    if (throwable instanceof Error) {
      throw (Error) throwable;
    }
  }

  /**

   *   throwIfUnchecked(failure);
   *   throw new AssertionError(failure);
   * }
   * </pre>
   *
   * @since 20.0
   */
  public static void throwIfUnchecked(Throwable throwable) {
    checkNotNull(throwable);
    if (throwable instanceof RuntimeException) {
      throw (RuntimeException) throwable;
    }
    if (throwable instanceof Error) {
      throw (Error) throwable;
    }
  }

  /**

      getList().addAll(0, null);
      fail("addAll(n, null) should throw");
    } catch (NullPointerException expected) {
    }
    expectUnchanged();
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  public void testAddAllAtIndex_negative() {
    try {
      getList().addAll(-1, MinimalCollection.of(e3()));
      fail("addAll(-1, e) should throw");
    } catch (IndexOutOfBoundsException expected) {
    }

    checkNotNull(timeoutUnit);
    try {
      return callable.call();
    } catch (RuntimeException e) {
      throw new UncheckedExecutionException(e);
    } catch (Exception e) {
      restoreInterruptIfIsInterruptedException(e);
      throw new ExecutionException(e);
    } catch (Error e) {
      throw new ExecutionError(e);
    }
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override

   * Iterable)}, except that it does not throw {@link IOException}.
   *
   * @since 11.0
   */
  @CanIgnoreReturnValue
  public final StringBuilder appendTo(
      StringBuilder builder, Iterator<? extends @Nullable Object> parts) {
    try {
      appendTo((Appendable) builder, parts);
    } catch (IOException impossible) {
      throw new AssertionError(impossible);
    }
    return builder;

  /**
   * Guaranteed to throw an exception and leave the underlying data unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final void add(@ParametricNullness E e) {
    throw new UnsupportedOperationException();
  }

  /**

        "Map.merge(absent, value, function) should return value",
        v3(),
        getMap()
            .merge(
                k3(),
                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(
                      "Should not call merge function if key was absent");
                }));
    expectAdded(e3());
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})

   * could throw during the invocation of that method. This is necessary because, e.g., a call to
   * {@code iterator().remove()} of an unmodifiable list could throw either {@link
   * IllegalStateException} or {@link UnsupportedOperationException}. Note that iterator
   * implementations should always throw one of the exceptions in a {@code PermittedExceptions}

    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  public void testAddAll_unsupportedNothing() {
    try {
      assertFalse(
          "addAll(nothing) should return false or throw", collection.addAll(emptyCollection()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_ADD)

  }

  /**
   * Guaranteed to throw an exception and leave the map unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  @CheckForNull
  public final Entry<K, V> pollFirstEntry() {
    throw new UnsupportedOperationException();
  }