This way we can replicate the geometries without paying extra cost to the DOM - so we can have invisible mouseover zones and emphasize borders on hover that would otherwise be covered by adjacent polygons. Another benefit of this for the sparklines is being able to pull the emphasized line to the top level, so none of the others are overlapping. This currently looks like:
This way we can replicate the geometries without paying extra cost to the DOM - so we can have invisible mouseover zones and emphasize borders on hover that would otherwise be covered by adjacent polygons. Another benefit of this for the sparklines is being able to pull the emphasized line to the top level, so none of the others are overlapping. This currently looks like: