code: def get(self):
      
      try:
        cluster = self.get_argument_cluster()
        role = self.get_argument_role()
        environ = self.get_argument_environ()
        topology_name = self.get_argument_topology()
        component = self.get_argument_component()
        metric_names = self.get_required_arguments_metricnames()
        start_time = self.get_argument_starttime()
        end_time = self.get_argument_endtime()
        self.validateInterval(start_time, end_time)
        instances = self.get_arguments(constants.PARAM_INSTANCE)
  
        topology = self.tracker.getTopologyByClusterRoleEnvironAndName(
            cluster, role, environ, topology_name)
        metrics = yield tornado.gen.Task(metricstimeline.getMetricsTimeline,
                                         topology.tmaster, component, metric_names,
                                         instances, int(start_time), int(end_time))
        self.write_success_response(metrics)
      except Exception as e:
        Log.debug(traceback.format_exc())
        self.write_error_response(e)
docs: get method