how to use a Service in javascript widget?

[Thomas Fjellstrom]

I've tried to "port" some C++ example code to a javascript widget to try and 
access the service operations in a data engine:

service = networkinfo.serviceForSource("manual");
// also tried:
// service = plasmoid.service("networkinfo", "manual")
// which complains that service isn't a function
op = service.operationDescription("addHost");
op.writeEntry("name", "boris");
job = service.startOperationCall(op);
job.finished.connect(function() { print("job done!"); });

Unfortunately the plasmoidviewer complains that op.writeEntry is not a 
function. Is this supposed to be possible in 4.4.4?

Just for kicks I tried waiting for a couple second before running that code, 
it didn't seem to help.

-- 
Thomas Fjellstrom
tfjellstrom at shaw.ca