code: func DeclareHTTPPortFlag(pluginName infra.PluginName, defaultPortOpts ...uint) {
  	var defaultPort string
  	if len(defaultPortOpts) > 0 {
  		defaultPort = string(defaultPortOpts[0])
  	} else {
  		defaultPort = DefaultHTTPPort
  	}
  
  	plugNameUpper := strings.ToUpper(string(pluginName))
  
  	usage := "Configure Agent' " + plugNameUpper + " server (port & timeouts); also set via '" +
  		plugNameUpper + config.EnvSuffix + "' env variable."
  	flag.String(httpPortFlag(pluginName), defaultPort, usage)
  }
docs: // DeclareHTTPPortFlag declares http port (with usage & default value) a flag for a particular plugin name