code: func (m *Martini) Run() {
  	port := os.Getenv("PORT")
  	if len(port) == 0 {
  		port = "3000"
  	}
  
  	host := os.Getenv("HOST")
  
  	m.RunOnAddr(host + ":" + port)
  }
docs: // Run the http server. Listening on os.GetEnv("PORT") or 3000 by default.