code: func (ftp *FTP) RawCmd(command string, args ...interface{}) (code int, line string) {
  	if ftp.debug {
  		log.Printf("Raw-> %s\n", fmt.Sprintf(command, args...))
  	}
  
  	code = -1
  	var err error
  	if err = ftp.send(command, args...); err != nil {
  		return code, ""
  	}
  	if line, err = ftp.receive(); err != nil {
  		return code, ""
  	}
  	code, err = strconv.Atoi(line[:3])
  	if ftp.debug {
  		log.Printf("Raw<-	<- %d \n", code)
  	}
  	return code, line
  }
docs: // RawCmd sends raw commands to the remote server. Returns response code as int and response as string.