'Test appending to an existing zipfile.'

def test_append_to_zip_file(self):

    with zipfile.ZipFile(TESTFN2, 'w', zipfile.ZIP_STORED) as zipfp:
        zipfp.write(TESTFN, TESTFN)
    with zipfile.ZipFile(TESTFN2, 'a', zipfile.ZIP_STORED) as zipfp:
        zipfp.writestr('strfile', self.data)
        self.assertEqual(zipfp.namelist(), [TESTFN, 'strfile'])
