code: function drawBars() {
              let bars;
  
              if (isAnimated) {
                  bars = svg.select('.chart-group').selectAll('.bar')
                      .data(dataZeroed);
  
                  if (isHorizontal) {
                      drawHorizontalBars(bars);
                  } else {
                      drawVerticalBars(bars);
                  }
  
                  bars = svg.select('.chart-group').selectAll('.bar')
                      .data(data);
  
                  if (isHorizontal) {
                      drawAnimatedHorizontalBars(bars);
                  } else {
                      drawAnimatedVerticalBars(bars);
                  }
  
                  // Exit
                  bars.exit()
                      .transition()
                      .style('opacity', 0)
                      .remove();
              } else {
                  bars = svg.select('.chart-group').selectAll('.bar')
                      .data(data);
  
                  if (isHorizontal) {
                      drawHorizontalBars(bars);
                  } else {
                      drawVerticalBars(bars);
                  }
  
                  // Exit
                  bars.exit()
                      .remove();
              }
  
          }
docs: Draws the bar elements within the chart group
  @private