def parse_stream(cls, iterable):
        """
        Parse a stream of messages into a stream of L{Task} instances.

        :param iterable: An iterable of serialized Eliot message dictionaries.

        :return: An iterable of parsed L{Task} instances. Remaining
            incomplete L{Task} will be returned when the input stream is
            exhausted.
        """
        parser = Parser()
        for message_dict in iterable:
            completed, parser = parser.add(message_dict)
            for task in completed:
                yield task
        for task in parser.incomplete_tasks():
            yield task
Parse a stream of messages into a stream of L{Task} instances.

        :param iterable: An iterable of serialized Eliot message dictionaries.

        :return: An iterable of parsed L{Task} instances. Remaining
            incomplete L{Task} will be returned when the input stream is
            exhausted.