Error in codex "wp_get_attachment_thumb_url()"

Hey there, i’m see this error in the function reference here:
http://codex.wordpress.org/Function_Reference/wp_get_attachment_thumb_url

the “Usage” description is wrong:
wp_get_attachment_thumb_url( $post_id );
This return false.

The correct reference should be (or something like this):
wp_get_attachment_thumb_url( get_post_thumbnail_id( get_the_ID() ) );

In the wrong reference, see the var $post_id (this is wrong), this funciton need the attachment id.

Sorry for my bad english.

Regards.
Maxi