#vulnerable code 
                              private BestPossibleStateOutput compute(ClusterEvent event, Map<String, Resource> resourceMap,
      CurrentStateOutput currentStateOutput) {
    ClusterDataCache cache = event.getAttribute(AttributeName.ClusterDataCache.name());
    // After compute all workflows and jobs, there are still task resources need to be DROPPED
    Map<String, Resource> restOfResources = new HashMap<>(resourceMap);
    BestPossibleStateOutput output = new BestPossibleStateOutput();
    final List<String> failureResources = new ArrayList<>();
    // Queues only for Workflows
    scheduleWorkflows(resourceMap, cache, restOfResources, failureResources, currentStateOutput, output);
    for (String jobName : cache.getDispatchedJobs()) {
      updateResourceMap(jobName, resourceMap, output.getPartitionStateMap(jobName).partitionSet());
      restOfResources.remove(jobName);
    }

    // Current rest of resources including: only current state left over ones
    for (Resource resource : restOfResources.values()) {
      if (!computeResourceBestPossibleState(event, cache, currentStateOutput, resource, output)) {
        failureResources.add(resource.getResourceName());
        LogUtil.logWarn(logger, _eventId,
            "Failed to calculate best possible states for " + resource.getResourceName());
      }
    }

    return output;
  } 
                            #location 10 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                              private BestPossibleStateOutput compute(ClusterEvent event, Map<String, Resource> resourceMap,
      CurrentStateOutput currentStateOutput) {
    ClusterDataCache cache = event.getAttribute(AttributeName.ClusterDataCache.name());
    // After compute all workflows and jobs, there are still task resources need to be DROPPED
    Map<String, Resource> restOfResources = new HashMap<>(resourceMap);
    BestPossibleStateOutput output = new BestPossibleStateOutput();
    final List<String> failureResources = new ArrayList<>();
    // Queues only for Workflows
    scheduleWorkflows(resourceMap, cache, restOfResources, failureResources, currentStateOutput, output);
    for (String jobName : cache.getDispatchedJobs()) {
      updateResourceMap(jobName, resourceMap, output.getPartitionStateMap(jobName).partitionSet());
      restOfResources.remove(jobName);
    }

    // Current rest of resources including: only current state left over ones
    // Original resource map contains workflows + jobs + other invalid resources
    // After removing workflows + jobs, only leftover ones will go over old rebalance pipeline.
    for (Resource resource : restOfResources.values()) {
      if (!computeResourceBestPossibleState(event, cache, currentStateOutput, resource, output)) {
        failureResources.add(resource.getResourceName());
        LogUtil.logWarn(logger, _eventId,
            "Failed to calculate best possible states for " + resource.getResourceName());
      }
    }

    return output;
  }