code: function drawTooltip(){
              tooltipTextContainer = svg.selectAll('.tooltip-group')
                  .append('g')
                  .classed('tooltip-text select-disable', true);
  
              tooltipBackground = tooltipTextContainer
                .append('rect')
                  .classed('tooltip-background', true)
                  .attr('width', width)
                  .attr('height', height)
                  .attr('rx', backgroundBorderRadius)
                  .attr('ry', backgroundBorderRadius)
                  .attr('y', - margin.top)
                  .attr('x', - margin.left)
                  .style('fill', bodyFillColor)
                  .style('stroke', borderStrokeColor)
                  .style('stroke-width', 1)
                  .style('pointer-events', 'none')
                  .style('opacity', 0.9);
          }
docs: Draws the different elements of the Tooltip box
  @return void