Draw polylines with arrows

[guizhen-wang]

Hi,
I planned to draw an path and add an arrow to the end of that path.
I followed the manual in this link (https://developers.google.com/maps/documentation/javascript/symbols) to modify the GMapsFx library. The new code passed the compile and build, but the arrow weren't shown on the map.
Did anyone ever do similar thing? Could you please share your thought?

Many thanks,