def from_node(index, value):
        """
        >>> h = TimelineHistory.from_node(1, 2)
        >>> h.lines
        []
        """
        try:
            lines = json.loads(value)
        except (TypeError, ValueError):
            lines = None
        if not isinstance(lines, list):
            lines = []
        return TimelineHistory(index, value, lines)
>>> h = TimelineHistory.from_node(1, 2)
        >>> h.lines
        []