code: def test_gather_tuples():
      a = (torch.zeros(1, 1), torch.zeros(2, 2))
      b = (torch.zeros(1, 1), torch.zeros(2, 2))
  
      ab = gather([Batch(a), Batch(b)])
  
      assert isinstance(ab, tuple)
      assert ab[0].size() == (2, 1)
      assert ab[1].size() == (4, 2)
  
file_path: pytorch/test/distributed/pipeline/sync/test_microbatch.py
imports: import pytest
  import torch
  import torch.cuda
  from torch.distributed.pipeline.sync.microbatch import Batch, check, gather, scatter
  from torch.testing._internal.common_utils import run_tests
label_desc: Use image node_id 8 for calling a global function with example usage: test_gather_tuples() without return types