code: func newDockerClient(c *Context) (*dockerutil.Client, error) {
  	host := c.String(FlagDockerHost)
  	certPath := c.String(FlagDockerCert)
  	authProvider, err := newAuthProvider(c)
  	if err != nil {
  		return nil, err
  	}
  
  	return dockerutil.NewClient(authProvider, host, certPath)
  }
docs: // DockerClient ========================