class BSON::Decimal128::Builder::ToString

def exponent
  @exponent ||= two_highest_bits_set? ?
      ((high_bits & 0x1fffe00000000000) >> 47) - Decimal128::EXPONENT_OFFSET :
      ((high_bits & 0x7fff800000000000) >> 49) - Decimal128::EXPONENT_OFFSET
end