CodeStepByStep

Define a class named TimeSpan. A TimeSpan object stores a span of time in hours and minutes (for example, the time span between 8:00am and 10:30am is 2 hours, 30 minutes). Each TimeSpan object should have the following public methods:

• new TimeSpan(hours, minutes)
  Constructs a TimeSpan object storing the given time span of hours and minutes.
• getHours()
  Returns the number of hours in this time span.
• getMinutes()
  Returns the number of minutes in this time span, between 0 and 59.
• add(hours, minutes)
  Adds the given amount of time to the span. For example, (2 hours, 15 min) + (1 hour, 45 min) = (4 hours). Assume that the parameters are valid: the hours are non-negative, and the minutes are between 0 and 59.
• add(timespan)
  Adds the given amount of time (stored as a time span) to the current time span.
• getTotalHours()
  Returns the total time in this time span as the real number of hours, such as 9.75 for (9 hours, 45 min).
• toString()
  Returns a string representation of the time span of hours and minutes, such as "28h46m".

The minutes should always be reported as being in the range of 0 to 59. That means that you may have to "carry" 60 minutes into a full hour.