code: def test_blockpartition():
      assert blockpartition.solve([1, 2, 3, 4, 5, 6], partitions=2) == [
          [1, 2, 3, 4],
          [5, 6],
      ]
  
imports: import time
  import pytest
  import torch
  from torch import nn
  from torch.distributed.pipeline.sync._balance import balance_by_size, balance_by_time, blockpartition
  from torch.distributed.pipeline.sync._balance.profile import layerwise_sandbox
  from torch.testing._internal.common_utils import run_tests
label_desc: Use image node_id 1 for calling a global function with example usage: test_blockpartition() without return types