chart = {
const svg = d3.select(DOM.svg(width, height));
const tip = svg.append('g');
const tipRect = tip.append("rect");
const tipText = tip.append('text').style("text-anchor", "middle");
svg
.append("g")
.selectAll("g")
.data(data_year)
.join("g")
.attr("transform", d => `translate(${x0(d[groupKey])},0)`)
.selectAll("rect")
.data(d => keys.map(key => ({ key, value: d[key] })))
.join("rect")
.attr("x", d => x1(d.key))
.attr("y", d => y(d.value))
.attr("width", x1.bandwidth())
.attr("height", d => y(0) - y(+d.value))
.attr("fill", d => color(d.key))
svg.append("g").call(xAxis);
svg.append("g").call(yAxis);
svg.append("g").call(legend);
return svg.node();
}