code: private void generateMaps() throws Exception {
          updateTaskComponentMap();
          this.defaultResources = new HashMap<>();
          this.userResources = new HashMap<>();
          this.executorData = new HashMap<>();
          this.registeredMetrics = new HashMap();
      }
docs: private ConcurrentHashMap<Integer, WorkerSlot> taskToNodePort;
  private HashMap<Integer, String> tasksToComponent;
  private Map<String, List<Integer>> componentToSortedTasks;
  private Map<String, Map<String, Fields>> componentToStreamToFields;
  private Map<String, Object> defaultResources;
  private Map<String, Object> userResources;
  private Map<String, Object> executorData;
  private Map registeredMetrics;
  
  @throws Exception