code: func FnClient(endPoint, certsDir string) (client *docker.Client, err error) {
  	if endPoint == "" {
  		endPoint = "npipe:////./pipe/docker_engine"
  	}
  	if certsDir != "" {
  		client, err = docker.NewTLSClient(endPoint, filepath.Join(certsDir, "cert.pem"), filepath.Join(certsDir, "key.pem"), filepath.Join(certsDir, "ca.pem"))
  		return
  	}
  	client, err = docker.NewClient(endPoint)
  	return
  }
docs: // FnClient instantiate a docker client
  // For datails https://docs.docker.com/docker-for-windows/faqs/#can-i-use-docker-for-windows-with-new-swarm-mode
  // on section "How do I connect to the remote Docker Engine API?"