code: def _gen_missing_api(api, mod_name):
      def _missing_api(*args, **kwargs):
          raise ImportError(
              'API "%s" is not supported by backend "%s".'
              " You can switch to other backends by setting"
              " the DGLBACKEND environment." % (api, mod_name)
          )
  
      return _missing_api
  
file_path: dgl/python/dgl/backend/__init__.py
imports: from __future__ import absolute_import
  import importlib
  import json
  import logging
  import os
  import sys
  from .None import backend
  from .set_default_backend import set_default_backend
label_desc: Use image node_id 1 for calling a global function with example usage: _gen_missing_api(api, mod_name) and returns: _missing_api