code: def func_set_import_onnx_config(config):
      def handle_source_func_list(func):
          source_func_list.append(func)
  
      def handle_target_func_list(func, opset):
          # regular to declare standard
          if opset.startswith("opset_"):
              opset = opset[len("opset_") :]
          target_func_list.append("{}@{}".format(func, opset))
  
      def map_target_to_source(func_list):
          _func_list = []
          target_set = set(func_list)
          for nnabla_func, impl_funcs in _onnx_func_info.items():
              if set(impl_funcs) <= target_set:
                  _func_list.append(nnabla_func)
          return _func_list
  
      source_func_list = []
      target_func_list = []
      with open(config, "r") as f:
          for func_decl in f.readlines():
              func_decl = func_decl.strip().split("@")
              if func_decl[0].startswith(";"):
                  # comment out
                  continue
              elif len(func_decl) == 1:
                  handle_source_func_list(func_decl[0])
              elif len(func_decl) == 2:
                  handle_target_func_list(func_decl[0], func_decl[1])
      if not source_func_list and not target_func_list:
          print("WARNING: function list seems empty!")
          return set()
  
      if target_func_list:
          func_list = map_target_to_source(target_func_list)
      else:
          func_list = source_func_list
      return set(func_list)
  
imports: import pickle
  import zlib
  from collections import OrderedDict
  from os.path import abspath, join, dirname, expanduser
  import glob
  import os
  import yaml
  import certifi
  import ssl
  from nnabla.utils import nnabla_pb2
  from nnabla.logger import logger
label_desc: Use image node_id 25 for calling a global function with example usage: func_set_import_onnx_config(config) and returns: set, _func_list, set