code: function handleMouseOver(el, d, chartWidth, chartHeight) {
              drawLegend(d);
              dispatcher.call('customMouseOver', el, d, d3Selection.mouse(el), [chartWidth, chartHeight]);
  
              if (hasHoverAnimation) {
                  // if the hovered slice is not the same as the last slice hovered
                  // after mouseout event, then shrink the last slice that was highlighted
                  if (lastHighlightedSlice && el !== lastHighlightedSlice) {
                      tweenGrowth(lastHighlightedSlice, externalRadius - radiusHoverOffset, pieHoverTransitionDuration);
                  }
                  if (highlightedSlice && el !== highlightedSlice) {
                      tweenGrowth(highlightedSlice, externalRadius - radiusHoverOffset);
                  }
                  tweenGrowth(el, externalRadius);
              }
  
          }
docs: Handles a path mouse over
  @return {void}
  @private