code: def create_and_check_decoder_model_past(
      self,
      config,
      input_ids,
      attention_mask,
      lm_labels,
  ):
      config.use_cache = True
      model = MBartDecoder(config=config).to(torch_device).eval()
      # first forward pass
      outputs = model(input_ids, use_cache=True)
      outputs_use_cache_conf = model(input_ids)
      outputs_no_past = model(input_ids, use_cache=False)
  
      self.parent.assertTrue(
          len(outputs) == len(outputs_use_cache_conf)
      )
      self.parent.assertTrue(len(outputs) == len(outputs_no_past) + 1)
  
      past_key_values = outputs["past_key_values"]
  
      # create hypothetical next token and extent to next_input_ids
      next_tokens = ids_tensor((self.batch_size, 1), config.vocab_size)
  
      # append to next input_ids and
      next_input_ids = torch.cat([input_ids, next_tokens], dim=-1)
  
      output_from_no_past = model(next_input_ids)["last_hidden_state"]
      output_from_past = model(
          next_tokens, past_key_values=past_key_values
      )["last_hidden_state"]
  
      # select random slice
      random_slice_idx = ids_tensor(
          (1,), output_from_past.shape[-1]
      ).item()
      output_from_no_past_slice = output_from_no_past[
          :, next_input_ids.shape[-1] - 1, random_slice_idx
      ].detach()
      output_from_past_slice = output_from_past[
          :, 0, random_slice_idx
      ].detach()
  
      # test that outputs are equal for slice
      assert torch.allclose(
          output_from_past_slice, output_from_no_past_slice, atol=1e-3
      )
  
imports: import copy
  import tempfile
  import unittest
  from transformers import MBartConfig, is_torch_available
  from transformers.testing_utils import require_sentencepiece, require_tokenizers, require_torch, require_torch_fp16, slow, torch_device
  from transformers.utils import cached_property
  from ...generation.test_utils import GenerationTesterMixin
  from ...test_configuration_common import ConfigTester
  from ...test_modeling_common import ModelTesterMixin, ids_tensor
  from ...test_pipeline_mixin import PipelineTesterMixin
label_desc: Use image node_id 3 for calling the MBartStandaloneDecoderModelTester obj's underlying member method code with example usage: obj.create_and_check_decoder_model_past(config, input_ids, attention_mask, lm_labels) without return types