code: def _construct_invalid_config_variations(config, backend_name):
      dataset_name, arch_name, identifier = config[
          len("lp://") :
      ].split("/")
      return [
          "lp://" + "/".join([backend_name]),
      ]
  
file_path: layout-parser/tests/test_model.py
imports: import pytest
  import cv2
  from layoutparser import load_json
  from layoutparser.models import *
label_desc: Use image node_id 2 for calling a global function with example usage: _construct_invalid_config_variations(config, backend_name) and returns: list