Add the following method to the TimeSpan class:
public void add(TimeSpan span)
Adds the given amount of time to this time span.
Recall the TimeSpan code from this chapter:
public class TimeSpan {
private int hours;
private int minutes;
public void add(int hours, int minutes) { ... }
public int getHours() { ... }
public int getMinutes() { ... }
public String toString() { ... }
// your code goes here
}