Cluster data structures
 

We are having trouble understanding exactly how to use these cluster data structures. Does anyone know exactly how to use them to display information on the dashboard? And on top of that, what exactly the methods for them do, and how to use them? And as a last point, why in the default code that came with the classmate, why are 3 clusters initialized, and only 1 has information added to it? That's what I understand to be happening.