'If url not in _tested, append a ?WSDL and check the response.
:param fuzzable_request: A fuzzable_request instance that contains
(among other things) the URL to test.'

def crawl(self, fuzzable_request):

    url = fuzzable_request.get_url().uri2url()
    url_string = url.url_string
    if (url_string not in self._already_tested):
        self._already_tested.add(url_string)
        wsdl_url_generator = self.wsdl_url_generator(url_string)
        self.worker_pool.map(self._do_request, wsdl_url_generator, chunksize=1)
