class CustomIterator<> implements Iterator<> 
{
    // Variable to retain current location information (a.k.a.: cursor)

    // constructor
    CustomIterator<>(CustomDataStructure obj) 
    {
        // initialize cursor
    }
      
    // Checks if the next element exists
    public boolean hasNext() 
    {
    }
      
    // moves the cursor/iterator to next element
    public T next() 
    {
    }
      
    // Used to remove an element. Implement only if needed
    public void remove() 
    {
        // Default throws UnsupportedOperationException.
    }
}