code: function drawAxis() {
              if (isHorizontal) {
                  svg.select('.x-axis-group .axis.x')
                      .attr('transform', `translate( 0, ${chartHeight} )`)
                      .call(xAxis);
  
                  svg.select('.y-axis-group.axis')
                      .attr('transform', `translate( ${-xAxisPadding.left}, 0)`)
                      .call(yAxis);
              } else {
                  svg.select('.x-axis-group .axis.x')
                      .attr('transform', `translate( 0, ${chartHeight} )`)
                      .call(xAxis);
  
                  svg.select('.y-axis-group.axis')
                      .attr('transform', `translate( ${-xAxisPadding.left}, 0)`)
                      .call(yAxis)
                      .call(adjustYTickLabels);
              }
  
              if (yAxisLabel) {
                  if (yAxisLabelEl) {
                      svg.selectAll('.y-axis-label-text').remove();
                  }
  
                  yAxisLabelEl = svg.select('.y-axis-label')
                      .append('text')
                          .classed('y-axis-label-text', true)
                          .attr('x', -chartHeight / 2)
                          .attr('y', yAxisLabelOffset)
                          .attr('text-anchor', 'middle')
                          .attr('transform', 'rotate(270 0 0)')
                          .text(yAxisLabel)
              }
          }
docs: Draws the x and y axis on the svg object within their
  respective groups
  @private