def TestNegativeResponse(self, prefix=None):
    is_broken = False
    if prefix:
      hostname = prefix
      warning_suffix = ' (%s)' % prefix
    else:
      hostname = 'test'
      warning_suffix = ''
    poison_test = '%s.nb%s.google.com.' % (hostname, random.random())
    (response, duration, error_msg) = self.TimedRequest('A', poison_test,
                                                        timeout=self.health_timeout*2)
    if not response:
      if not error_msg:
        error_msg = 'No response'
      is_broken = True
    elif response.answer:
      error_msg = 'NXDOMAIN Hijacking' + warning_suffix

    return (is_broken, error_msg, duration)
Test for NXDOMAIN hijaaking.
dataset/ETHPy150Open catap/namebench/libnamebench/health_checks.py/NameServerHealthChecks.TestNegativeResponse