from "gds polygon subcell". Previously both polygons and paths
were put into subcells named polygonXXXXX (substitute numbers
for XXXXX). Now polygons go into cells named polygonXXXXX and
paths go into cells named pathXXXXX. This makes it easier to
keep track of the original path. NOTE: The path centerline
should be kept as a cell property in this case, and the path
options like endcap style can also be held as properties. The
polygon boundary should be treated similarly.