Zoom & Brush in Stacked Area Chart

Question

Playing with Mike's Zoom & Brush. How to change this when my area is stacked? In this case I use layer function

var layer = svg.selectAll(".layer")
  .data(stack(values))
  .enter().append("g").append("path")
    .attr("class", "layer")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")")
    .style("fill", (d,i) => d3.color(colors[i]))
    .attr("d", area);

But how redraw chart after zoom? What instead

focus.append("path")
  .datum(values)
  .attr("class", "area")
  .attr("d", area);

and

focus.select(".area").attr("d", area);

?