'Loads user data from service'

def user_data(self, access_token, *args, **kwargs):

    token = access_token.key
    params = {'token': token, 'key': backend_setting(self, self.SETTINGS_KEY_NAME)}
    url = ((TRELLO_USER_DETAILS_URL + '?') + urlencode(params))
    try:
        return simplejson.load(dsa_urlopen(url))
    except ValueError:
        return None
