code: @Override
    public float floatValue() {
      @SuppressWarnings("cast")
      float fValue = (float) (value & UNSIGNED_MASK);
      if (value < 0) {
        fValue += 0x1.0p63f;
      }
      return fValue;
    }
docs: Returns the value of this {@code UnsignedLong} as a {@code float}, analogous to a widening
  primitive conversion from {@code long} to {@code float}, and correctly rounded.