it's not possible to inspect sim.util.geo.MasonGeometry.userData in
GeoMason. I'm sending a fix, which enables it.
In addition, I had to uncomment the constructor "public
DrawInfo2D(Rectangle2D.Double draw, Rectangle2D.Double clip)" in
mason/sim/portrayal/DrawInfo2D.java, but maybe this should be fixed in
GeoMason class sim.portrayal.geo.GeomVectorFieldPortrayal (line 254,