':return: True if the FuzzableRequest was previously unknown'

@requires_setup
def add_fuzzable_request(self, fuzzable_request):

    if (not isinstance(fuzzable_request, FuzzableRequest)):
        msg = 'add_fuzzable_request    requires    a    FuzzableRequest    as    parameter,    got    "%s"    instead.'
        raise TypeError((msg % type(fuzzable_request)))
    self.add_url(fuzzable_request.get_url())
    return self.fuzzable_requests.add(fuzzable_request)
