add: return ""; 
context: function getHandlerInfoForType(aURI, aPropertyString){  // get current selected type  var handler = HANDLER_URI(getLiteralForContentType(aURI, "value"));  var source = gRDF.GetResource(handler);  var property = gRDF.GetResource(NC_RDF(aPropertyString));  var target = gDS.GetTarget(source, property, true);  if (target) {    target = target.QueryInterface(Components.interfaces.nsIRDFLiteral);    return target.Value;  }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/00afe27dac931e94c429509a41be3327b9416993/overrideHandler.js/clean/xpfe/components/prefwindow/resources/content/overrideHandler.js