fails:Time#subsec returns the fractional seconds as a Rational for a Time constructed with a Rational number of seconds
fails:Time#subsec returns the fractional seconds as a Rational for a Time constructed with a Float number of seconds
fails:Time#subsec returns the fractional seconds as a Rational for a Time constructed with an Integer number of microseconds
fails:Time#subsec returns the fractional seconds as a Rational for a Time constructed with an Rational number of microseconds
fails:Time#subsec returns the fractional seconds as a Rational for a Time constructed with an Float number of microseconds
