This looks really good. I think you need to also define a

def __init__(self, instance):
    super(Anonymous, self).__init__(instance, dn=None)

This way there is "no way" someone can make anonymous with a dn that is not none.

Once you do that, I'll review again, and will merge :)

@firstyear changes has been done as per you suggestion

Is this comment for init? Or for bind? Whitespace looks a bit weird ...

@firstyear white space and comment removed

Why did you remove this function?

@firstyear git mistake , now its ok

389-ds-base is moving from Pagure to Github. This means that new issues and pull requests
will be accepted only in 389-ds-base's github repository.

This pull request has been cloned to Github as issue and is available here:
- https://github.com/389ds/389-ds-base/issues/3273

If you want to continue to work on the PR, please navigate to the github issue,
download the patch from the attachments and file a new pull request.

Thank you for understanding. We apologize for all inconvenience.