The stub of append() should look like this: 
   void ArrayQueue::append(const Item& it) {
   }
The append() method should behave as follows:
  1. If the queue is full, throw a FullQueueException;
  2. Otherwise:
    1. Store it in myArray at index myLast;
    2. Add 1 to myLast (modulus myCapacity); and
    3. Add 1 to mySize.