def testNegativeInfinityPacked(self, message_module):
    golden_data = (b'\xA2\x06\x04\x00\x00\x80\xFF'
                   b'\xAA\x06\x08\x00\x00\x00\x00\x00\x00\xF0\xFF')
    golden_message = message_module.TestPackedTypes()
    golden_message.ParseFromString(golden_data)
    self.assertTrue(IsNegInf(golden_message.packed_float[0]))
    self.assertTrue(IsNegInf(golden_message.packed_double[0]))
    self.assertEqual(golden_data, golden_message.SerializeToString())