code: func (fl *Flags) Register(f *flag.FlagSet) {
  	f.StringVar(&fl.ConfigFile, "ts-mon-config-file", fl.ConfigFile,
  		"path to a JSON config file that contains suitable values for "+
  			"\"endpoint\" and \"credentials\" for this machine. This config file is "+
  			"intended to be shared by all processes on the machine, as the values "+
  			"depend on the machine's position in the network, IP whitelisting and "+
  			"deployment of credentials.")
  	f.StringVar(&fl.Endpoint, "ts-mon-endpoint", fl.Endpoint,
  		"url (including file://, https://, pubsub://project/topic) to post "+
  			"monitoring metrics to. If set, overrides the value in "+
  			"--ts-mon-config-file")
  	f.StringVar(&fl.Credentials, "ts-mon-credentials", fl.Credentials,
  		"path to a pkcs8 json credential file. If set, overrides the value in "+
  			"--ts-mon-config-file")
  	f.StringVar(&fl.ActAs, "ts-mon-act-as", fl.ActAs,
  		"(advanced) a service account email to impersonate when authenticating to "+
  			"tsmon backends. Uses 'iam' scope and serviceAccountTokenCreator role. "+
  			"If set, overrides the value in --ts-mon-config-file")
  	f.Var(&fl.Flush, "ts-mon-flush",
  		"metric push behavior: manual (only send when Flush() is called), or auto "+
  			"(send automatically every --ts-mon-flush-interval)")
  	f.DurationVar(&fl.FlushInterval, "ts-mon-flush-interval", fl.FlushInterval,
  		"automatically push metrics on this interval if --ts-mon-flush=auto")
  
  	fl.Target.Register(f)
  }
docs: // Register adds tsmon related flags to a FlagSet.