This example demonstrates an interactive force-directed graph where users can push and pull nodes, with selected nodes remaining fixed in place during continuous layout. The visualization uses the gojs library (`go.ForceDirectedLayout`, `go.Diagram`, `go.Shape`, `go.TextBlock`) to compute spring and electrical forces that automatically space nodes apart while dragging. The implementation customizes the layout to reuse a cached `ForceDirectedNetwork`, updating bounds for selected nodes and recalculating positions only when the structure changes. A “SelectionMoved” event triggers an extra layout pass after each drag interaction.