def METHOD_NAME(self, idx, worker):
    logger.info("Starting worker '%s'", worker.name)
    metrics_exporter = None
    if self.prometheus:
        from zentral.utils.prometheus import PrometheusMetricsExporter
        prometheus_port = self.prometheus_base_port + idx
        metrics_exporter = PrometheusMetricsExporter(prometheus_port)
    elif self.statsd:
        from zentral.utils.statsd import StatsdMetricsExporter
        metrics_exporter = StatsdMetricsExporter(self.statsd_host, self.statsd_port, self.statsd_prefix)
    p = Process(target=worker.run,
                kwargs={"metrics_exporter": metrics_exporter},
                name=worker.name)
    p.daemon = 1
    p.start()
    self.processes[idx] = (worker, p)
    if self.prometheus:
        self.prometheus_targets[idx] = {
            "targets": ["{}:{}".format(self.external_hostname, prometheus_port)],
            "labels": {"job": worker.name}
        }