This example displays a basic line chart showing COVID-19 data, with a text summary of the loaded dataset printed above the visualization. The chart renders using D3 v7’s `csv` loader to fetch data from a GitHub Gist, while React manages the component state and asynchronous data loading. The `message` function calculates and displays the dataset’s size in kilobytes, row count, and column count using `d3.csvFormat`. The visualization itself is minimal, focusing on the data summary rather than a graphical line plot, and runs within a React 16.9 application using `ReactDOM.render`.