How can I use the edit_post function in PyTumblr?

I am trying to edit some posts in my tumblr blog using PyTumblr and the edit_post function, but I can't figure out exactly what parameters are needed. I try to put the tags parameter but it's not accepted.

I have tried this:

client = pytumblr.TumblrRestClient(CONSUMER_KEY, CONSUMER_SECRET,
                                   OAUTH_TOKEN, OAUTH_TOKEN_SECRET)
client.edit_post('nameofblog', {'id': 39228373})

And it gives me the following error:

TypeError: edit_post() takes exactly 2 arguments (3 given)

Any ideas?

This is the function:

    def edit_post(self, blogname, **kwargs):
            """
    Edits a post with a given id

    :param blogname: a string, the url of the blog you want to edit
    :param tags: a list of tags that you want applied to the post
    :param tweet: a string, the customized tweet that you want
    :param date: a string, the GMT date and time of the post
    :param format: a string, sets the format type of the post. html or markdown
    :param slug: a string, a short text summary to the end of the post url

    :returns: a dict created from the JSON response
    """
      url = "/v2/blog/%s/post/edit" % blogname
      return self.send_api_request('post', url, kwargs)