'Merges another series config dict in with the current one.'

def merge_config(self, task, config):

    native_series = self.prepare_config(task.config.get(u'series', {}))
    merging_series = self.prepare_config(config)
    task.config[u'series'] = self.combine_series_lists(merging_series, native_series, log_once=True)
    return task.config[u'series']
