code: function drawVerticalExtendedLine() {
              baseLine = svg.select('.grid-lines-group')
                  .selectAll('line.extended-y-line')
                  .data([0])
                  .enter()
                    .append('line')
                      .attr('class', 'extended-y-line')
                      .attr('y1', (xAxisPadding.bottom))
                      .attr('y2', chartHeight)
                      .attr('x1', 0)
                      .attr('x2', 0);
          }
docs: Draws a vertical line to extend y-axis till the edges
  @return {void}