code: public static Period positive(final Period self) {
          return !self.isNegative() ? self : self.withDays(Math.abs(self.getDays()))
                  .withMonths(Math.abs(self.getMonths()))
                  .withYears(Math.abs(self.getYears()));
      }
docs: Supports the unary plus operator; returns a {@link java.time.Period} with all unit values positive.
  For example, a period of "2 years, -3 months, and -4 days" would result in a period of
  "2 years, 3 months, and 4 days." No normalization is performed.
  
  @param self a Period
  @return a positive Period
  @since 2.5.0