code: public Period minus(TemporalAmount amountToSubtract) {
          Period amount = Period.from(amountToSubtract);
          return create(
                  Jdk8Methods.safeSubtract(years, amount.years),
                  Jdk8Methods.safeSubtract(months, amount.months),
                  Jdk8Methods.safeSubtract(days, amount.days));
      }
docs: Returns a copy of this period with the specified amount subtracted.
  <p>
  This input amount is converted to a {@code Period} using {@code from(TemporalAmount)}.
  This operates separately on the years, months and days.
  <p>
  For example, "1 year, 6 months and 3 days" minus "2 years, 2 months and 2 days"
  returns "-1 years, 4 months and 1 day".
  <p>
  This instance is immutable and unaffected by this method call.
  
  @param amountToSubtract  the period to subtract, not null
  @return a {@code Period} based on this period with the requested period subtracted, not null
  @throws ArithmeticException if numeric overflow occurs