'Return the stats object for a specific item=value in JSON format.
Stats should be a list of dict (processlist, network...)'

def get_stats_value(self, item, value):

    if (not isinstance(self.stats, list)):
        return None
    else:
        if value.isdigit():
            value = int(value)
        try:
            return self._json_dumps({value: [i for i in self.stats if (i[item] == value)]})
        except (KeyError, ValueError) as e:
            logger.error('Cannot    get    item({})=value({})    ({})'.format(item, value, e))
            return None
