'The C{cookies} dict passed to the L{client.HTTPDownloader}
initializer is used to populate the I{Cookie} header included in the
request sent to the server.'

def test_downloadCookies(self):

    output = self.mktemp()
    factory = client._makeGetterFactory(self.getURL('cookiemirror'), client.HTTPDownloader, fileOrName=output, cookies={'foo': 'bar'})
    def cbFinished(ignored):
        self.assertEqual(FilePath(output).getContent(), "[('foo',    'bar')]")
    factory.deferred.addCallback(cbFinished)
    return factory.deferred
