'Set the metrics stats name.
The stats_name is a string used to access the metris through scales: scales.getStats()[<stats_name>]
Default is \'cassandra-<num>\'.'

def set_stats_name(self, stats_name):

    if (self.stats_name == stats_name):
        return
    if (stats_name in scales._Stats.stats):
        raise ValueError('"{0}"    already    exists    in    stats.'.format(stats_name))
    stats = scales._Stats.stats[self.stats_name]
    del scales._Stats.stats[self.stats_name]
    self.stats_name = stats_name
    scales._Stats.stats[self.stats_name] = stats
