Documentation Error on ActiveResource::Errors

Errors add_to_base has an example like so:

my_folder.errors.add_to_base("This folder has been tagged as frozen")

my_folder.valid?

1. => false

my_folder.errors.on_base

1. => ["You can't edit an existing folder", "This folder has been tagged as frozen"]

This is incorrect because valid? clear the errors first. Here is an example:

(rdb:1) @invitation.errors.add_to_base("foo")

["foo"]

(rdb:1) @invitation.errors

#, @errors={"base"=>["foo"]}>

(rdb:1) @invitation.valid?

true

(rdb:1)