def testHighPrecisionDoublePrinting(self, message_module):
    msg = message_module.TestAllTypes()
    msg.optional_double = 0.12345678912345678
    if sys.version_info >= (3,):
      self.assertEqual(str(msg), 'optional_double: 0.12345678912345678\n')
    else:
      self.assertEqual(str(msg), 'optional_double: 0.123456789123\n')