code: function horizontalBarsTween(d) {
              let node = d3Selection.select(this),
                  i = d3Interpolate.interpolateRound(0, xScale(getValue(d))),
                  j = d3Interpolate.interpolateNumber(0, 1);
  
              return function (t) {
                  node.attr('width', i(t))
                      .style('opacity', j(t));
              }
          }
docs: Animation tween of horizontal bars
  @param  {obj} d data of bar
  @return {void}