NS_OpenURI(nsIStreamListener     *listener, nsISupports           *context,
NS_OpenURI(nsIInputStream       **result,
NS_OpenURI(nsIStreamListener     *listener,            nsISupports           *context,            nsIURI                *uri,           nsIIOService          *ioService = nsnull,     // pass in nsIIOService to optimize callers           nsILoadGroup          *loadGroup = nsnull,           nsIInterfaceRequestor *callbacks = nsnull,           PRUint32               loadFlags = nsIRequest::LOAD_NORMAL){    nsresult rv;    nsCOMPtr<nsIChannel> channel;    rv = NS_NewChannel(getter_AddRefs(channel), uri, ioService,                       loadGroup, callbacks, loadFlags);    if (NS_SUCCEEDED(rv))        rv = channel->AsyncOpen(listener, context);    return rv;}