fresh block
This example demonstrates a minimal introductory visualization, displaying a short text message centered within an SVG canvas. The code uses D3 v4 to select the body element, append an SVG container sized at 960 by 500 pixels, and add a single text element. The text is styled with a 36-pixel monospace font and positioned at coordinates (120, 200). The implementation relies on basic D3 selection and attribute methods, such as `d3.select`, `append`, and `attr`, to construct the static visual. No data source is loaded; instead, the visualization serves as a simple template for testing the Blockbuilder tool.