Adds the given result to the list

        :param _type: type of the state of the test (TestState.failure, TestState.error, ...)
        :param test: the test
        :param exc_info: additional execution information

def add_result(self, _type, test, exc_info=None):
        """
        Adds the given result to the list

        :param _type: type of the state of the test (TestState.failure, TestState.error, ...)
        :param test: the test
        :param exc_info: additional execution information
        """
        if exc_info is not None:
            exc_info = FrozenExcInfo(exc_info)
        test.time_taken = time.time() - self.start_time
        test._outcome = None
        self.result_queue.put((_type, test, exc_info))