code: def get_metrics(cluster, environment, topology, timerange, query, role=None):
    '''
    Get the metrics for a topology from tracker
    :param cluster:
    :param environment:
    :param topology:
    :param timerange:
    :param query:
    :param role:
    :return:
    '''
    params = dict(
        cluster=cluster,
        environ=environment,
        topology=topology,
        starttime=timerange[0],
        endtime=timerange[1],
        query=query)
  
    if role is not None:
      params['role'] = role
  
    request_url = tornado.httputil.url_concat(
        create_url(METRICS_QUERY_URL_FMT), params
    )
  
    logging.info("get_metrics %s", request_url)
    raise tornado.gen.Return((yield fetch_url_as_json(request_url))f get_metrics(cluster, environment, topology, timerange, query, role=None):
    '''
    Get the metrics for a topology from tracker
    :param cluster:
    :param environment:
    :param topology:
    :param timerange:
    :param query:
    :param role:
    :return:
    '''
    params = dict(
        cluster=cluster,
        environ=environment,
        topology=topology,
        starttime=timerange[0],
        endtime=timerange[1],
        query=query)
  
    if role is not None:
      params['role'] = role
  
    request_url = tornado.httputil.url_concat(
        create_url(METRICS_QUERY_URL_FMT), params
    )
  
    logging.info("get_metrics %s", request_url)
    raise tornado.gen.Return((yield fetch_url_as_json(request_url)))
docs: Get the metrics for a topology from tracker
    :param cluster:
    :param environment:
    :param topology:
    :param timerange:
    :param query:
    :param role:
    :return: