code: def add_multiprocessing_configvars():
      # Test if the env variable is set
      var = os.getenv("OMP_NUM_THREADS", None)
      if var:
          try:
              int(var)
          except ValueError:
              raise TypeError(
                  f"The environment variable OMP_NUM_THREADS should be a number, got '{var}'."
              )
          else:
              default_openmp = int(var) != 1
      else:
          # Check the number of cores availables.
          count = os.cpu_count()
          if count is None:
              _logger.warning(
                  "We are not able to detect the number of CPU cores."
                  " We disable openmp by default. To remove this"
                  " warning, set the environment variable"
                  " OMP_NUM_THREADS to the number of threads you"
                  " want pytensor to use."
              )
          default_openmp = count > 1
  
      # Disable it by default for now as currently only the ConvOp supports
      # it, and this causes slowdown by default as we do not disable it for
      # too small convolution.
      default_openmp = False
  
      config.add(
          "openmp",
          "Allow (or not) parallel computation on the CPU with OpenMP. "
          "This is the default value used when creating an Op that "
          "supports OpenMP parallelization. It is preferable to define it "
          "via the PyTensor configuration file ~/.pytensorrc or with the "
          "environment variable PYTENSOR_FLAGS. Parallelization is only "
          "done for some operations that implement it, and even for "
          "operations that implement parallelism, each operation is free "
          "to respect this flag or not. You can control the number of "
          "threads used with the environment variable OMP_NUM_THREADS."
          " If it is set to 1, we disable openmp in PyTensor by default.",
          BoolParam(default_openmp),
          in_c_key=False,
      )
  
      config.add(
          "openmp_elemwise_minsize",
          "If OpenMP is enabled, this is the minimum size of vectors "
          "for which the openmp parallelization is enabled "
          "in element wise ops.",
          IntParam(200000),
          in_c_key=False,
      )
  
imports: import errno
  import logging
  import os
  import platform
  import re
  import socket
  import sys
  import textwrap
  import numpy
  from setuptools._distutils.spawn import find_executable
  import pytensor
  from pytensor.configparser import BoolParam, ConfigParam, DeviceParam, EnumStr, FloatParam, IntParam, StrParam, _create_default_config
  from pytensor.utils import LOCAL_BITWIDTH, PYTHON_INT_BITWIDTH, call_subprocess_Popen, maybe_add_to_os_environ_pathlist, output_subprocess_Popen
label_desc: Use image node_id 28 for calling a global function with example usage: add_multiprocessing_configvars() without return types