code: def test_model_main_input_name(self):
      for model_class in self.all_model_classes:
          model_signature = inspect.signature(
              getattr(model_class, "__call__")
          )
          # The main input is the name of the argument after `self`
          observed_main_input_name = list(
              model_signature.parameters.keys()
          )[1]
          self.assertEqual(
              model_class.main_input_name, observed_main_input_name
          )
  
imports: import copy
  import inspect
  import json
  import random
  import tempfile
  import unittest
  from typing import List, Tuple
  import numpy
  import transformers
  from huggingface_hub import HfFolder, delete_repo, set_access_token
  from requests.exceptions import HTTPError
  from transformers import BertConfig, is_flax_available, is_torch_available
  from transformers.models.auto import get_values
  from transformers.testing_utils import TOKEN, USER, CaptureLogger, is_pt_flax_cross_test, is_staging_test, require_flax, torch_device
  from transformers.utils import logging
  from transformers.utils.generic import ModelOutput
label_desc: Use image node_id 25 for calling the FlaxModelTesterMixin obj's underlying member method code with example usage: obj.test_model_main_input_name() without return types