public static class TwoArg {
    /** Action to take on a null param. */
    public enum Action {
      THROW_A_NPE {
        @Override
        public void act() {
          throw new NullPointerException();
        }
      },
      THROW_OTHER {
        @Override
        public void act() {
          throw new FooException();
        }
      },
      JUST_RETURN {
        @Override

      cause.setStackTrace(combined);
    }
    if (cause instanceof Exception) {
      throw (Exception) cause;
    }
    if (cause instanceof Error) {
      throw (Error) cause;
    }
    // The cause is a weird kind of Throwable, so throw the outer exception.
    throw e;
  }

  private static Set<Method> findInterruptibleMethods(Class<?> interfaceType) {

      @CheckForNull Object p4) {
    if (reference == null) {
      throw new NullPointerException(lenientFormat(errorMessageTemplate, p1, p2, p3, p4));
    }
    return reference;
  }

  /*
   * All recent hotspots (as of 2009) *really* like to have the natural code
   *
   * if (guardExpression) {
   *    throw new BadException(messageExpression);
   * }
   *

  public final boolean add(E e) {
    throw new UnsupportedOperationException();
  }

  public final boolean remove(@Nullable Object object) {
    throw new UnsupportedOperationException();
  }

  public final boolean addAll(Collection<? extends E> newElements) {
    throw new UnsupportedOperationException();
  }

  public final boolean removeAll(Collection<?> oldElements) {
    throw new UnsupportedOperationException();
  }

    Comparable<?> endpoint() {
      throw new IllegalStateException("range unbounded on this side");
    }

    @Override
    boolean isLessThan(Comparable<?> value) {
      return true;
    }

    @Override
    BoundType typeAsLowerBound() {
      throw new IllegalStateException();
    }

    @Override
    BoundType typeAsUpperBound() {

    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the {@code RangeMap} unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final void remove(Range<K> range) {

    if (t != null) {
      if (t instanceof Error) throw (Error) t;
      else if (t instanceof RuntimeException) throw (RuntimeException) t;
      else if (t instanceof Exception) throw (Exception) t;
      else {
        AssertionFailedError afe = new AssertionFailedError(t.toString());
        afe.initCause(t);
        throw afe;
      }
    }

   *   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) {
    }