code: def run_dist(rank, world_size, port):
      colossalai.launch(
          config=dict(),
          rank=rank,
          world_size=world_size,
          host="localhost",
          port=port,
          backend="nccl",
      )
      MOE_MANAGER.setup(parallel="EP")
      run_zero_optim_test(rank, world_size, stage=1)
      run_zero_optim_test(rank, world_size, stage=2)
  
file_path: ColossalAI/tests/test_moe/test_moe_zero_optim.py
imports: import pytest
  import torch
  import colossalai
  from colossalai.booster import Booster
  from colossalai.booster.plugin import LowLevelZeroPlugin
  from colossalai.booster.plugin.low_level_zero_plugin import LowLevelZeroModel
  from colossalai.moe.manager import MOE_MANAGER
  from colossalai.testing import rerun_if_address_is_in_use, spawn
  from tests.test_moe.moe_utils import MoeGradientHandler, MoeModel
label_desc: Use image node_id 4 for calling a global function with example usage: run_dist(rank, world_size, port) without return types