code: def _init_stream_pool():
      global _device_stream_pool_map
      for i in range(MAX_GPU_PER_ACTOR):
          _device_stream_pool_map[i] = StreamPool(i)
  
file_path: ray/python/ray/util/collective/collective_group/cuda_stream.py
imports: import logging
  import threading
  import cupy
  from ray.util.collective.collective_group import nccl_util
  from ray.util.collective.const import ENV
label_desc: Use image node_id 1 for calling a global function with example usage: _init_stream_pool() without return types