This example shows a D3 tree layout with multiple parent nodes, where shared child nodes like "Supply and demand" and "Foreign worker" appear under both "Government of the United States" and "Stock market." The visualization deduplicates nodes by ID using Underscore.js’s `_.uniq` and remaps links to the unique targets. It uses `d3.tree`, `d3.hierarchy`, and `d3.linkHorizontal` for layout and path generation, with SVG text labels and interactive zoom and transition animations applied via `d3.zoom` and `transition`. Data is loaded from a local JSON file.