code: func New(flagset plugin.FlagSet) http.RoundTripper {
  	if flagset == nil {
  		return &transport{}
  	}
  	flagset.AddExtraUsage(extraUsage)
  	return &transport{
  		cert: flagset.String("tls_cert", "", "TLS client certificate file for fetching profile and symbols"),
  		key:  flagset.String("tls_key", "", "TLS private key file for fetching profile and symbols"),
  		ca:   flagset.String("tls_ca", "", "TLS CA certs file for fetching profile and symbols"),
  	}
  }
docs: // New returns a round tripper for making requests with the
  // specified cert, key, and ca. The flags tls_cert, tls_key, and tls_ca are
  // added to the flagset to allow a user to specify the cert, key, and ca. If
  // the flagset is nil, no flags will be added, and users will not be able to
  // use these flags.