def wiki_update(self, title, new_title=None, page_body=None):
        """Action to lets you update a wiki page (Requires login) (UNTESTED).

        Parameters:
            title (str): The title of the wiki page to update.
            new_title (str): The new title of the wiki page.
            page_body (str): The new body of the wiki page.
        """
        params = {
            'title': title,
            'wiki_page[title]': new_title,
            'wiki_page[body]': page_body
            }
        return self._get('wiki/update', params, method='PUT')