'The CGI script is never called with the Proxy header passed through.'

def test_noProxyPassthrough(self):

    cgiFilename = self.writeCGI(HEADER_OUTPUT_CGI)
    portnum = self.startServer(cgiFilename)
    url = ('http://localhost:%d/cgi' % (portnum,))
    url = url.encode('ascii')
    agent = client.Agent(reactor)
    headers = http_headers.Headers({'Proxy': ['foo'], 'X-Innocent-Header': ['bar']})
    d = agent.request('GET', url, headers=headers)
    def checkResponse(response):
        headers = json.loads(response.decode('ascii'))
        self.assertEqual(set(headers.keys()), {'HTTP_HOST', 'HTTP_CONNECTION', 'HTTP_X_INNOCENT_HEADER'})
    d.addCallback(client.readBody)
    d.addCallback(checkResponse)
    return d
