* @throws X1 when the given throwable is of the declared type X1
   * @throws X2 when the given throwable is of the declared type X2
   */
  public <X1 extends Exception, X2 extends Exception> RuntimeException rethrow(
      Throwable e, Class<X1> declaredType1, Class<X2> declaredType2) throws IOException, X1, X2 {
    checkNotNull(e);
    thrown = e;
    throwIfInstanceOf(e, IOException.class);

      int result = BigIntegerMath.log2(x, HALF_UP);
      BigInteger x2 = x.pow(2);
      // x^2 < 2^(2 * result + 1), or else we would have rounded up
      assertThat(ZERO.setBit(2 * result + 1)).isGreaterThan(x2);
      // x^2 >= 2^(2 * result - 1), or else we would have rounded down
      assertTrue(result == 0 || ZERO.setBit(2 * result - 1).compareTo(x2) <= 0);
    }
  }

  public void testLog2HalfDown() {

        //
        // To determine which side of logFloor.5 the logarithm is,
        // we compare x^2 to 2^(2 * logFloor + 1).
        BigInteger x2 = x.pow(2);
        int logX2Floor = x2.bitLength() - 1;
        return (logX2Floor < 2 * logFloor + 1) ? logFloor : logFloor + 1;
    }
    throw new AssertionError();
  }

  /*

      retVal &= Enums.getIfPresent(enumType, sampleData[i & 255]).isPresent();
    }
    return retVal;
  }

  private enum SmallEnum {
    X0,
    X1,
    X2
  }

  private enum MediumEnum {
    X0,
    X1,
    X2,
    X3,
    X4,
    X5,
    X6,
    X7,
    X8,
    X9,
    X10,
    X11,
    X12,
    X13,
    X14,
    X15,
    X16,
    X17,

   *     null}.
   */
  @Deprecated
  @J2ktIncompatible
  @GwtIncompatible // propagateIfInstanceOf
  public static <X1 extends Throwable, X2 extends Throwable> void propagateIfPossible(
      @Nullable Throwable throwable, Class<X1> declaredType1, Class<X2> declaredType2)
      throws X1, X2 {
    checkNotNull(declaredType2);
    propagateIfInstanceOf(throwable, declaredType1);
    propagateIfPossible(throwable, declaredType2);
  }

    private final ImmutableIntArray parent;

    private AsList(ImmutableIntArray parent) {
      this.parent = parent;
    }

    // inherit: isEmpty, containsAll, toArray x2, iterator, listIterator, stream, forEach, mutations

    @Override
    public int size() {
      return parent.length();
    }

    @Override
    public Integer get(int index) {

    private final ImmutableLongArray parent;

    private AsList(ImmutableLongArray parent) {
      this.parent = parent;
    }

    // inherit: isEmpty, containsAll, toArray x2, iterator, listIterator, stream, forEach, mutations

    @Override
    public int size() {
      return parent.length();
    }

    @Override
    public Long get(int index) {

    /*
     * For an explanation of the basic principle behind this check, see
     * https://stackoverflow.com/a/35754308/28465
     *
     * In that explanation's notation, our `overlap` check would be `x1 < y2 && y1 < x2`. We've
     * flipped one part of the check so that we're using "less than" in both cases (rather than a
     * mix of "less than" and "greater than"). We've also switched to "strictly less than" rather