code: func getEnvBool(v string, def bool) bool {
  	r := os.Getenv(v)
  	if r == "" {
  		return def
  	}
  
  	switch strings.ToLower(r[0:1]) {
  	case "t", "y", "1":
  		return true
  	}
  
  	return false
  }
docs: // getEnvBool returns boolean from environment variable.