This example renders a directed graph as a sentence parse tree, showing the hierarchical structure of the phrase "This is an example sentence." The nodes represent grammatical categories (TOP, S, NP, VP) and tokens (This, is, an, example, .), with edges connecting parents to children. Code uses the dagre-d3 library’s `Graph`, `render`, and `setNode`/`setEdge` APIs to compute a layered layout and draw it on an SVG. Custom CSS styles round the node corners and highlight token nodes (type-TK) in teal. The D3 selection `d3.select('svg')` appends a group for the rendered output.