* must not both be identical to the values given in the first mapping. If only the {@code x}
     * values are identical, the transformation is vertical. If only the {@code y} values are
     * identical, the transformation is horizontal (i.e. the slope is zero).
     */
    public LinearTransformation and(double x2, double y2) {

      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
      assertTrue(ZERO.setBit(2 * result + 1).compareTo(x2) > 0);
      // 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() {

      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
      assertTrue(ZERO.setBit(2 * result + 1).compareTo(x2) > 0);
      // 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() {

      buf[bufLen++] = getChar(h);

      int x0 = buf[bufLen - 1] & 0xff;
      int x1 = buf[bufLen - 2] & 0xff;
      int x2 = buf[bufLen - 3] & 0xff;
      int x3 = buf[bufLen / 2] & 0xff;
      buf[((x0 << 16) + (x1 << 8) + x2) % bufLen] ^= x3;
      buf[((x1 << 16) + (x2 << 8) + x3) % bufLen] ^= i % 256;
    }
    assertEquals(0xeaa3b1c985261632L, h);
  }

  private static long remix(long h) {

      buf[bufLen++] = getChar(h);

      int x0 = buf[bufLen - 1] & 0xff;
      int x1 = buf[bufLen - 2] & 0xff;
      int x2 = buf[bufLen - 3] & 0xff;
      int x3 = buf[bufLen / 2] & 0xff;
      buf[((x0 << 16) + (x1 << 8) + x2) % bufLen] ^= x3;
      buf[((x1 << 16) + (x2 << 8) + x3) % bufLen] ^= i % 256;
    }
    assertEquals(0x7a1d67c50ec7e167L, h);
  }

  private static long remix(long h) {

      buf[bufLen++] = getChar(h);

      int x0 = buf[bufLen - 1] & 0xff;
      int x1 = buf[bufLen - 2] & 0xff;
      int x2 = buf[bufLen - 3] & 0xff;
      int x3 = buf[bufLen / 2] & 0xff;
      buf[((x0 << 16) + (x1 << 8) + x2) % bufLen] ^= x3;
      buf[((x1 << 16) + (x2 << 8) + x3) % bufLen] ^= i % 256;
    }
    assertEquals(0x7a1d67c50ec7e167L, h);
  }

  private static long remix(long h) {

      buf[bufLen++] = getChar(h);

      int x0 = buf[bufLen - 1] & 0xff;
      int x1 = buf[bufLen - 2] & 0xff;
      int x2 = buf[bufLen - 3] & 0xff;
      int x3 = buf[bufLen / 2] & 0xff;
      buf[((x0 << 16) + (x1 << 8) + x2) % bufLen] ^= x3;
      buf[((x1 << 16) + (x2 << 8) + x3) % bufLen] ^= i % 256;
    }
    assertEquals(0xeaa3b1c985261632L, h);
  }

  private static long remix(long h) {

   * @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);

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

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