This example demonstrates how to create a striped visual effect using SVG rectangles masked by a circular window. It uses D3’s `select`, `range`, and data joins to generate 100 horizontal bars, each with a height of 10 pixels and a vertical offset of 20 pixels, filling the full viewport width. The bars are rendered with a `mask` attribute referencing a circular mask, so only the area inside the circle is visible. The code exercises D3’s declarative data binding and the SVG mask API to achieve the clipped pattern.