This example visualizes the co-occurrence network of characters in *Les Misérables*, using D3 v4’s force-directed simulation. Nodes represent individual characters, colored by their group, while links show relationships weighted by their value. The graph is rendered as SVG circles and lines, with node labels available via tooltips. The simulation includes charge and center forces, and nodes are draggable. The data is loaded from a local JSON file, and the tick function is present but commented out, meaning the layout is computed but node/link positions are not updated on screen—a possible bug in the example.