Ublic class appointment{// date date; private int length; ///public appointment(date thedate, int thelength){//date = thedate; date = new date(thedate); length = thelength; }//copy constructorpublic appointment(appointment another){//this. date = another. date; //made a shallow copy of another. datethis. date = new date(another. date); this. length = another. length; }tostring - returns its representation as a stringpublic string tostring(){return "date: " + date + " length: " + length + " minutes"; }//extend - extends the time by a given amountpublic void extend(int minutes)