code: func (d *DockerHelper) GetContainerNum(all bool) int {
  	containers, err := d.client.ContainerList(getContext(), types.ContainerListOptions{All: all})
  	if err != nil {
  		panic(fmt.Sprintf("Error list containers: %v", err))
  	}
  	return len(containers)
  }
docs: // GetContainerNum returns container number in the system, panics when error occurs