code: func (c *Config) NodeName() string {
  	name := c.name()
  	// Backwards compatibility: previous versions used title-cased "Geth", keep that.
  	if name == "geth" || name == "geth-testnet" {
  		name = "Geth"
  	}
  	if c.UserIdent != "" {
  		name += "/" + c.UserIdent
  	}
  	if c.Version != "" {
  		name += "/v" + c.Version
  	}
  	name += "/" + runtime.GOOS + "-" + runtime.GOARCH
  	name += "/" + runtime.Version()
  	return name
  }
docs: // NodeName returns the devp2p node identifier.