The stub of append() should look like this:
   void LinkedQueue::append(const Item& it) {
   }
The append() method should behave as follows:

  1. Try the following: Catch the std::bad_alloc exception it might throw; if that occurs, throw a FullQueueException.
  2. If the queue is empty: Otherwise:
  3. Make myLastPtr point at the new node.
  4. Increment mySize.