code: function drawArea() {
              if (brushArea) {
                  svg.selectAll('.brush-area').remove();
              }
  
              // Create and configure the area generator
              brushArea = d3Shape.area()
                  .x(({date}) => xScale(date))
                  .y0(chartHeight)
                  .y1(({value}) => yScale(value))
                  .curve(d3Shape.curveBasis);
  
              // Create the area path
              svg.select('.chart-group')
                .append('path')
                  .datum(data)
                  .attr('class', 'brush-area')
                  .attr('d', brushArea);
          }
docs: Draws the area that is going to represent the data
  
  @return {void}