public IntArrayBag clone( )
   {  // Clone an IntArrayBag object.
      IntArrayBag answer;
      
      try
      {
         answer = (IntArrayBag) super.clone( );
      }
      catch (CloneNotSupportedException e)
      {  // This exception should not occur. But if it does, it would probably
         // indicate a programming error that made super.clone unavailable.
         // The most common error would be forgetting the "Implements Cloneable"
         // clause at the start of this class.
         throw new RuntimeException
         ("This class does not implement Cloneable");
      }
      
      answer.data = data.clone( );
      
      return answer;
   }