This example visualizes the top five countries by population as a bar chart of empty, gray-outlined rectangles. It demonstrates how to scaffold a visualization with arbitrary nested layouts by rendering fixed-height placeholders for each country. The code uses D3.js (version 3.5.5) with an ordinal scale and range bands to position the bars, an SVG axis for labels, and a custom tick formatter that abbreviates billions as “B.” Data is loaded from a CSV file listing 2015 population estimates, with the x-axis mapped to country names and the y-axis left unencoded for future flexibility.