Expose get_config() on ModelTesters (#12812)

* Expose get_config() on ModelTesters

* Typo

templates/adding_a_new_model/cookiecutter-template-{{cookiecutter.modelname}}/test_modeling_{{cookiecutter.lowercase_modelname}}.py

@@ -22,6 +22,7 @@ from tests.test_modeling_common import floats_tensor
 from transformers import is_torch_available
 from transformers.testing_utils import require_torch, slow, torch_device
 
+from transformers import {{cookiecutter.camelcase_modelname}}Config
 from .test_configuration_common import ConfigTester
 from .test_modeling_common import ModelTesterMixin, ids_tensor, random_attention_mask
 
@@ -30,7 +31,6 @@ if is_torch_available():
     import torch
 
     from transformers import (
-        {{cookiecutter.camelcase_modelname}}Config,
         {{cookiecutter.camelcase_modelname}}ForCausalLM,
         {{cookiecutter.camelcase_modelname}}ForMaskedLM,
         {{cookiecutter.camelcase_modelname}}ForMultipleChoice,
@@ -112,7 +112,12 @@ class {{cookiecutter.camelcase_modelname}}ModelTester:
             token_labels = ids_tensor([self.batch_size, self.seq_length], self.num_labels)
             choice_labels = ids_tensor([self.batch_size], self.num_choices)
 
-        config = {{cookiecutter.camelcase_modelname}}Config(
+        config = self.get_config()
+
+        return config, input_ids, token_type_ids, input_mask, sequence_labels, token_labels, choice_labels
+
+    def get_config(self):
+        return {{cookiecutter.camelcase_modelname}}Config(
             vocab_size=self.vocab_size,
             hidden_size=self.hidden_size,
             num_hidden_layers=self.num_hidden_layers,
@@ -127,8 +132,6 @@ class {{cookiecutter.camelcase_modelname}}ModelTester:
             initializer_range=self.initializer_range,
         )
 
-        return config, input_ids, token_type_ids, input_mask, sequence_labels, token_labels, choice_labels
-
     def prepare_config_and_inputs_for_decoder(self):
         (
             config,