code: def save_result(result, result_dir, filename, remove_duplicate=""):
      import json
  
      result_file = os.path.join(
          result_dir, "%s_rank%d.json" % (filename, get_rank())
      )
      final_result_file = os.path.join(result_dir, "%s.json" % filename)
  
      json.dump(result, open(result_file, "w"))
  
      if is_dist_avail_and_initialized():
          dist.barrier()
  
      if is_main_process():
          logging.warning(
              "rank %d starts merging results." % get_rank()
          )
          # combine results from all processes
          result = []
  
          for rank in range(get_world_size()):
              result_file = os.path.join(
                  result_dir, "%s_rank%d.json" % (filename, rank)
              )
              res = json.load(open(result_file, "r"))
              result += res
  
          if remove_duplicate:
              result_new = []
              id_list = []
              for res in result:
                  if res[remove_duplicate] not in id_list:
                      id_list.append(res[remove_duplicate])
                      result_new.append(res)
              result = result_new
  
          json.dump(result, open(final_result_file, "w"))
          print("result file saved to %s" % final_result_file)
  
      return final_result_file
  
imports: import logging
  import os
  import torch
  import torch.distributed
  from lavis.common.dist_utils import get_rank, get_world_size, is_main_process, is_dist_avail_and_initialized
  from lavis.common.logger import MetricLogger, SmoothedValue
  from lavis.common.registry import registry
  from lavis.datasets.data_utils import prepare_sample
label_desc: Use image node_id 15 for calling the BaseTask obj's underlying member method code with example usage: obj.save_result(result, result_dir, filename, remove_duplicate) and returns: final_result_file