public SingleGeometryObject() : base()
 {
     type        = "Point";
     coordinates = new PositionObject();
 }
 public SingleGeometryObject(float longitude, float latitude) : base()
 {
     type        = "Point";
     coordinates = new PositionObject(longitude, latitude);
 }
 public SingleGeometryObject(JSONObject jsonObject) : base(jsonObject)
 {
     coordinates = new PositionObject(jsonObject["coordinates"]);
 }