public Period plusDays(long daysToAdd){
  if (daysToAdd == 0) {
    return this;
  }
  return create(years,months,Math.toIntExact(Math.addExact(days,daysToAdd)));
}

public Period plusDays ( long daysToAdd ) { if ( daysToAdd == 0 ) { return this ; } return create ( years , months , Math . toIntExact ( Math . addExact ( days , daysToAdd ) ) ) ; }
returns a copy of this period with the specified days added . < p > this adds the amount to the days unit in a copy of this period . the years and months units are unaffected . for example , " 1 year , 6 months and 3 days " plus 2 days returns " 1 year , 6 months and 5 days " . < p > this instance is immutable and unaffected by this method call .
