This example shows a stacked bar chart where each bar represents a group, and the bar is divided into colored segments corresponding to subgroups. The chart loads CSV data from a GitHub URL using `d3.csv`, and defines the subgroups from the data's column headers. It uses `d3.scaleBand` for the x-axis, `d3.scaleLinear` for the y-axis, and `d3.scaleOrdinal` for the color palette. The bars are created by stacking the data with `d3.stack` and rendering each segment as an SVG `rect` within a `g` element.