`GetID` in the `Claims` interface ?

Is there a special consideration for the absence of the GetID() function?

https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.7

https://github.com/golang-jwt/jwt/blob/8aa5d6cef84fa859f10fed5db50bee48efc5f160/claims.go#L9-L16