code: def torch_parallel_backend():
      try:
          match = re.search(
              "^ATen parallel backend: (?P<backend>.*)$",
              torch._C._parallel_info(),
              re.MULTILINE,
          )
          if match is None:
              return None
          backend = match.group("backend")
          if backend == "OpenMP":
              return "AT_PARALLEL_OPENMP"
          if backend == "native thread pool":
              return "AT_PARALLEL_NATIVE"
          if backend == "native thread pool and TBB":
              return "AT_PARALLEL_NATIVE_TBB"
      except (NameError, AttributeError):  # no torch or no binaries
          warnings.warn("Could not determine torch parallel_info.")
      return None
  
file_path: MONAI/setup.py
imports: from __future__ import annotations
  import glob
  import os
  import re
  import sys
  import warnings
  import pkg_resources
  from setuptools import find_packages, setup
  import versioneer
label_desc: Use image node_id 1 for calling a global function with example usage: torch_parallel_backend() and returns: None, None, str, str, str