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

public Period plusMonths ( long monthsToAdd ) { if ( monthsToAdd == 0 ) { return this ; } return create ( years , Math . toIntExact ( Math . addExact ( months , monthsToAdd ) ) , days ) ; }
returns a copy of this period with the specified months added . < p > this adds the amount to the months unit in a copy of this period . the years and days units are unaffected . for example , " 1 year , 6 months and 3 days " plus 2 months returns " 1 year , 8 months and 3 days " . < p > this instance is immutable and unaffected by this method call .
