code: def update(self, issue, **kwargs):
          
          url = issue.url
  
          response = self.session.patch(url, json.dumps(kwargs))
  
          assert response.status_code == 200
          return json.loads(response.content)
docs: Update an existing issue on Github.
          For JSON data returned by Github refer:
          https://developer.github.com/v3/issues/#edit-an-issue
  
          :param issue: object existing issue
          :returns: dict of JSON data returned by Github.
          :rtype: `dict`