code: func (l *BeeLogger) mustLogDebug(message string, file string, line int, args ...interface{}) {
  	if !debugMode {
  		return
  	}
  
  	// Change the output to Stderr
  	l.SetOutput(os.Stderr)
  
  	// Create the log record
  	record := LogRecord{
  		ID:       fmt.Sprintf("%04d", atomic.AddUint64(&sequenceNo, 1)),
  		Level:    l.getColorLevel(levelDebug),
  		Message:  fmt.Sprintf(message, args...),
  		LineNo:   line,
  		Filename: filepath.Base(file),
  	}
  	err := debugLogRecordTemplate.Execute(l.output, record)
  	if err != nil {
  		panic(err)
  	}
  }
docs: // mustLogDebug logs a debug message only if debug mode
  // is enabled. i.e. DEBUG_ENABLED="1"