tenfourfox/netwerk/test/unit/test_sockettransportsvc_available.js

function run_test() {
  try {
    var sts = Components.classes["@mozilla.org/network/socket-transport-service;1"]
                        .getService(Components.interfaces.nsISocketTransportService);
  } catch(e) {}

  do_check_true(!!sts);
}