code: public static String geometryToJson(int wkid, Geometry geometry) {
  		return GeometryEngine.geometryToJson(
  				wkid > 0 ? SpatialReference.create(wkid) : null, geometry);
  	}
docs: Exports the specified geometry instance to it's JSON representation.
  
  See OperatorExportToJson.
  
  @see GeometryEngine#geometryToJson(SpatialReference spatialiReference,
  Geometry geometry)
  @param wkid
  The spatial reference Well Known ID to be used for the JSON
  representation.
  @param geometry
  The geometry to be exported to JSON.
  @return The JSON representation of the specified Geometry.