code: def _check_backend_availability(backend: types.Backend):
      """Check whether the backend is available."""
      if backend == types.Backend.GLOO:
          if not gloo_available():
              raise RuntimeError("GLOO is not available.")
      elif backend == types.Backend.NCCL:
          if not nccl_available():
              raise RuntimeError("NCCL is not available.")
  
imports: import logging
  import os
  from typing import List
  import numpy
  import ray
  from ray.util.collective import types
label_desc: Use image node_id 27 for calling a global function with example usage: _check_backend_availability(backend) without return types