Strange problem when setting TerrainData.heightmapResolution

Unity Engine
1

The code snippet below always prints a result of 33 (the default TerrainData.heightmapResolution) even right after I change it to 17. This doesn’t seem to make any sense, especially since the same code used to work. Does Unity now treat heightmapResolution as read-only, or is my machine haunted by gremlins?

var td:TerrainData = new TerrainData();
td.heightmapResolution = 17; 
print (td.heightmapResolution);
2

I think I found the solution to my own problem, and will post it here in case someone else has a similar problem:
Apparently, 33 is the lowest possible resolution for a terrain, hence setting it lower will not work.