NOTE: In this sample, the views are stacked, and the buttons above allow switching between the views. The initial state should show a grid layout of nodes in the Topology View with only the first two buttons enabled. When drilling down to a flat list of data (e.g., Demo Navigation Hint) the Topology View should be shown (with only first two buttons enabled). When drilling down to a graph (e.g., Demo Topology), the Topology View should be shown (with all three buttons enabled).