code: func (c *Container) GetStopSignal() string {
  	if c.stopSignal == "" {
  		return defaultStopSignal
  	}
  	cleanSignal := strings.TrimPrefix(strings.ToUpper(c.stopSignal), "SIG")
  	_, ok := signal.SignalMap[cleanSignal]
  	if !ok {
  		return defaultStopSignal
  	}
  	return cleanSignal
  }
docs: // GetStopSignal returns the container's own stop signal configured from the
  // image configuration or the default one.