please complete the code and write the main class(test class) :

ClockDisplay

public class ClockDisplay{

private NumberDisplay hours;

private NumberDisplay minutes;

Private String displayString;

public ClockDisplay() {

//constructor init members w/limits

}

public ClockDisplay(int hr, int min) {

//init members and setTime

}

public void setTime(int hr, int min) {

//set time for hour, min

}

public void timeTick(){

//inc min, check min, inc hr if min=0

}

public String getTime() {

//return hour and min as string

}

}

ClockDisplay -hour: Number Display -minute: Number Display -displayString: String +ClockDisplay() +ClockDisplay(int, int) +setTime(int, int): void +getTime(): String +timeTick():void