* >= 0.5 and signifFloor is odd (which is true if both the 0.5 bit and the 1 bit are set).
     */
    boolean increment =
        (twiceSignifFloor & 1) != 0 && ((signifFloor & 1) != 0 || absX.getLowestSetBit() < shift);
    long signifRounded = increment ? signifFloor + 1 : signifFloor;
    long bits = (long) (exponent + EXPONENT_BIAS) << SIGNIFICAND_BITS;
    bits += signifRounded;
    /*

     * >= 0.5 and signifFloor is odd (which is true if both the 0.5 bit and the 1 bit are set).
     */
    boolean increment =
        (twiceSignifFloor & 1) != 0 && ((signifFloor & 1) != 0 || absX.getLowestSetBit() < shift);
    long signifRounded = increment ? signifFloor + 1 : signifFloor;
    long bits = (long) (exponent + EXPONENT_BIAS) << SIGNIFICAND_BITS;
    bits += signifRounded;
    /*

  }

  /** Returns {@code true} if {@code x} represents a power of two. */
  public static boolean isPowerOfTwo(BigInteger x) {
    checkNotNull(x);
    return x.signum() > 0 && x.getLowestSetBit() == x.bitLength() - 1;
  }

  /**
   * Returns the base-2 logarithm of {@code x}, rounded according to the specified rounding mode.
   *
   * @throws IllegalArgumentException if {@code x <= 0}

  }

  /** Returns {@code true} if {@code x} represents a power of two. */
  public static boolean isPowerOfTwo(BigInteger x) {
    checkNotNull(x);
    return x.signum() > 0 && x.getLowestSetBit() == x.bitLength() - 1;
  }

  /**
   * Returns the base-2 logarithm of {@code x}, rounded according to the specified rounding mode.
   *
   * @throws IllegalArgumentException if {@code x <= 0}