code: def check_missing_backends():
      """
      Checks if all backends are installed (otherwise the check of this script is incomplete). Will error in the CI if
      that's not the case but only throw a warning for users running this.
      """
      missing_backends = []
      if not is_torch_available():
          missing_backends.append("PyTorch")
      if not is_tf_available():
          missing_backends.append("TensorFlow")
      if not is_flax_available():
          missing_backends.append("Flax")
      if len(missing_backends) > 0:
          missing = ", ".join(missing_backends)
          if (
              os.getenv("TRANSFORMERS_IS_CI", "").upper()
              in ENV_VARS_TRUE_VALUES
          ):
              raise Exception(
                  "Full repo consistency checks require all backends to be installed (with `pip install -e '.[dev]'` in the "
                  f"Transformers repo, the following are missing: {missing}."
              )
          else:
              warnings.warn(
                  "Full repo consistency checks require all backends to be installed (with `pip install -e '.[dev]'` in the "
                  f"Transformers repo, the following are missing: {missing}. While it's probably fine as long as you "
                  "didn't make any change in one of those backends modeling files, you should probably execute the "
                  "command above to be on the safe side."
              )
  
imports: import inspect
  import os
  import re
  import sys
  import types
  import warnings
  from collections import OrderedDict
  from difflib import get_close_matches
  from pathlib import Path
  from typing import List, Tuple
  from transformers import is_flax_available, is_tf_available, is_torch_available
  from transformers.models.auto import get_values
  from transformers.models.auto.configuration_auto import CONFIG_MAPPING_NAMES
  from transformers.models.auto.feature_extraction_auto import FEATURE_EXTRACTOR_MAPPING_NAMES
  from transformers.models.auto.image_processing_auto import IMAGE_PROCESSOR_MAPPING_NAMES
  from transformers.models.auto.processing_auto import PROCESSOR_MAPPING_NAMES
  from transformers.models.auto.tokenization_auto import TOKENIZER_MAPPING_NAMES
  from transformers.utils import ENV_VARS_TRUE_VALUES, direct_transformers_import
label_desc: Use image node_id 1 for calling a global function with example usage: check_missing_backends() without return types