'Purge single file from CloudFlare\'s cache.
:param url: URL to the file to purge from cache.
:type url: ``str``'

def ex_purge_cached_file(self, zone, url):

    params = {'z': zone.domain, 'url': url}
    self.connection.set_context({'zone_domain': zone.domain})
    resp = self.connection.request(action='zone_file_purge', params=params)
    result = resp.object
    return (result.get('result', None) == 'success')
