This example shows a small network graph of eight friends, with nodes labeled by name and grouped by color, connected by ten weighted links. The graph is laid out using `d3.layout.force`, with link thickness proportional to the data’s `weight` attribute. Nodes are rendered as brown circles and red text, and the simulation updates positions on each tick. Data is loaded from a local `data.json` file, and the visualization is drawn to an SVG canvas using D3 v4 and v2 libraries.