PlaceholderChannel* channel = new PlaceholderChannel(); if (! channel)
PlaceHolderRequest* request = new PlaceHolderRequest(); if (! request)
PlaceholderChannel::Create(nsIChannel** aResult){    PlaceholderChannel* channel = new PlaceholderChannel();    if (! channel)        return NS_ERROR_OUT_OF_MEMORY;    *aResult = channel;    NS_ADDREF(*aResult);    return NS_OK;}