context.getDataConnector HttpConnector

Hi,
I'm trying to use HttpConnector from Javascript to load a specific valueset, but it doesn't work.
I'm using the script from the tutorial for providing a custom data set at https://jazz.net/wiki/bin/view/Main/DataSourceValueSetProviders#HTTP_Connector , but the script fails at the instruction:

var connector= context.getDataConnector("HttpConnector");

I'm using the RTC v3.0.1.3.

Has anybody successfully done that tutorial in RTC 3.0.1.3?
Any suggestions?

Thanks in advance,
Marco Delato