code: def test_cat_all(self):
      if DistributedHelper.rank == 0:
          ts = torch.full(
              (10 + 1, 5), DistributedHelper.rank, dtype=torch.long
          )
      else:
          ts = torch.full(
              (10, 5), DistributedHelper.rank, dtype=torch.long
          )
      device = DistributedHelper.make_device()
  
      if device.type == "cuda":
          # Additional test: tensors do not need to be on the default device
          DistributedHelper.cat_all(ts)
  
      ts = ts.to(device)
  
      concatenated_tensor = DistributedHelper.cat_all(ts)
  
      self.assertEqual(device, concatenated_tensor.device)
  
      expect = torch.empty(
          (DistributedHelper.world_size * 10 + 1, 5), dtype=torch.long
      ).to(device)
      for rank in range(DistributedHelper.world_size):
          if rank == 0:
              expect[rank * 10 : (rank + 1) * 10 + 1] = rank
          else:
              expect[1 + rank * 10 : 1 + (rank + 1) * 10] = rank
  
      self.assertTrue(torch.equal(concatenated_tensor, expect))
  
imports: import os
  import random
  import shutil
  import tempfile
  import time
  import unittest
  import numpy
  import torch
  import torch.distributed
  from torch.nn import Module
  from torch.nn.parallel import DistributedDataParallel
  from avalanche.benchmarks.scenarios.deprecated.generators import dataset_benchmark
  from avalanche.benchmarks.utils.classification_dataset import _make_taskaware_tensor_classification_dataset
  from avalanche.distributed import DistributedHelper
  from avalanche.distributed.distributed_helper import RollingSeedContext, BroadcastSeedContext
  from avalanche.models import SimpleMLP, as_multitask
  from avalanche.models.utils import avalanche_model_adaptation
  from avalanche.training.determinism.rng_manager import RNGManager
  from tests.distributed.distributed_test_utils import check_skip_distributed_slow_test, check_skip_distributed_test, suppress_dst_tests_output, common_dst_tests_setup
label_desc: Use image node_id 6 for calling the DistributedHelperTests obj's underlying member method code with example usage: obj.test_cat_all() without return types