nsresult res = nsComponentManager::CreateInstance(NS_MIME_CONVERTER_CONTRACTID, nsnull, NS_GET_IID(nsIMimeConverter), (void **)&converter);
nsresult res = CallCreateInstance(NS_MIME_CONVERTER_CONTRACTID, &converter);
MIME_B64EncoderInit(nsresult (*PR_CALLBACK output_fn) (const char *buf, PRInt32 size, void *closure), void *closure) {  MimeEncoderData *returnEncoderData = nsnull;  nsIMimeConverter *converter;  nsresult res = nsComponentManager::CreateInstance(NS_MIME_CONVERTER_CONTRACTID, nsnull,                                            NS_GET_IID(nsIMimeConverter), (void **)&converter);  if (NS_SUCCEEDED(res) && nsnull != converter)   {    res = converter->B64EncoderInit(output_fn, closure, &returnEncoderData);    NS_RELEASE(converter);  }  return NS_SUCCEEDED(res) ? returnEncoderData : nsnull;}