>>> ClusterConfig.from_node(1, '{') is None
        False

def from_node(index, data, modify_index=None):
        """
        >>> ClusterConfig.from_node(1, '{') is None
        False
        """

        try:
            data = json.loads(data)
        except (TypeError, ValueError):
            data = None
            modify_index = 0
        if not isinstance(data, dict):
            data = {}
        return ClusterConfig(index, data, index if modify_index is None else modify_index)