code: def check_one_step_transform(rank, world_size, port):
      disable_existing_loggers()
      launch(
          config={},
          rank=rank,
          world_size=world_size,
          host="localhost",
          port=port,
          backend="nccl",
      )
      # [[0, 1],
      #  [2, 3]]
      device_mesh = DeviceMesh(
          physical_mesh_id, mesh_shape, init_process_group=True
      )
  
      dim_partition_dict = {0: [0], 1: [1]}
      # DistSpec:
      #     shard_sequence: S0,S1,R
      #     device_mesh_shape: (2, 2)
      sharding_spec = ShardingSpec(
          dim_size=3, dim_partition_dict=dim_partition_dict
      )
      layout = Layout(
          device_mesh=device_mesh,
          sharding_spec=sharding_spec,
          global_shape=global_shape,
      )
  
      rst_dict = layout_converter.all_gather_transform_layouts(layout)
  
      assert "[R, S1, R]" in [
          str(all_gather_layout.sharding_spec.sharding_sequence)
          for all_gather_layout in rst_dict.keys()
      ]
      assert "[S0, R, R]" in [
          str(all_gather_layout.sharding_spec.sharding_sequence)
          for all_gather_layout in rst_dict.keys()
      ]
  
      dim_partition_dict_all2all = {0: [0], 1: [1]}
      # DistSpec:
      #     shard_sequence: S0,S1,R
      #     device_mesh_shape: (4, 4)
      sharding_spec_all2all = ShardingSpec(
          dim_size=3, dim_partition_dict=dim_partition_dict_all2all
      )
      layout_all2all = Layout(
          device_mesh=device_mesh,
          sharding_spec=sharding_spec_all2all,
          global_shape=global_shape,
      )
  
      rst_dict_all2all = layout_converter.all_to_all_transform_layout(
          layout_all2all
      )
  
      assert "[S01, R, R]" in [
          str(all2all_layout.sharding_spec.sharding_sequence)
          for all2all_layout in rst_dict_all2all.keys()
      ]
      assert "[R, S1, S0]" in [
          str(all2all_layout.sharding_spec.sharding_sequence)
          for all2all_layout in rst_dict_all2all.keys()
      ]
      assert "[S0, R, S1]" in [
          str(all2all_layout.sharding_spec.sharding_sequence)
          for all2all_layout in rst_dict_all2all.keys()
      ]
  
      dim_partition_shard = {0: [0]}
      # DistSpec:
      #     shard_sequence: S0,R,R
      #     device_mesh_shape: (4, 4)
      sharding_spec_shard = ShardingSpec(
          dim_size=3, dim_partition_dict=dim_partition_shard
      )
      shard_layout = Layout(
          device_mesh=device_mesh,
          sharding_spec=sharding_spec_shard,
          global_shape=global_shape,
      )
  
      rst_dict_shard = layout_converter.shard_transform_layout(
          shard_layout
      )
  
      assert "[S01, R, R]" in [
          str(shard_layout.sharding_spec.sharding_sequence)
          for shard_layout in rst_dict_shard.keys()
      ]
      assert "[S0, S1, R]" in [
          str(shard_layout.sharding_spec.sharding_sequence)
          for shard_layout in rst_dict_shard.keys()
      ]
      assert "[S0, R, S1]" in [
          str(shard_layout.sharding_spec.sharding_sequence)
          for shard_layout in rst_dict_shard.keys()
      ]
  
file_path: ColossalAI/tests/test_tensor/test_dtensor/test_layout_converter.py
imports: import math
  import pytest
  import torch
  from colossalai.device.device_mesh import DeviceMesh
  from colossalai.initialize import launch
  from colossalai.logging import disable_existing_loggers
  from colossalai.tensor.d_tensor.comm_spec import CollectiveCommPattern
  from colossalai.tensor.d_tensor.layout import Layout
  from colossalai.tensor.d_tensor.layout_converter import LayoutConverter
  from colossalai.tensor.d_tensor.sharding_spec import ShardingSpec
  from colossalai.testing import rerun_if_address_is_in_use, spawn
label_desc: Use image node_id 1 for calling a global function with example usage: check_one_step_transform(rank, world_size, port) without return types