rem: var rval = this._sandBox.FindProxyForURL(testURI, testHost); 
add: try { var rval = this._sandBox.FindProxyForURL(testURI, testHost); } catch (e) { throw new XPCSafeJSObjectWrapper(e); } 
context:     getProxyForURI: function(testURI, testHost) {        if (!("FindProxyForURL" in this._sandBox))            return null;        // Call the original function        var rval = this._sandBox.FindProxyForURL(testURI, testHost);        return rval;    }
meta: 10520	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/10520/809490bccbfcc9bb93bdbeea078d97171604995b/nsProxyAutoConfig.js/clean/netwerk/base/src/nsProxyAutoConfig.js