code: def test_seq2seq_max_length(self):
      batch = self.tokenizer(
          self.src_text,
          padding=True,
          truncation=True,
          max_length=3,
          return_tensors="pt",
      )
      targets = self.tokenizer(
          text_target=self.tgt_text,
          padding=True,
          truncation=True,
          max_length=10,
          return_tensors="pt",
      )
      labels = targets["input_ids"]
      batch["decoder_input_ids"] = shift_tokens_right(
          labels, self.tokenizer.pad_token_id
      )
  
      self.assertEqual(batch.input_ids.shape[1], 3)
      self.assertEqual(batch.decoder_input_ids.shape[1], 10)
  
imports: import tempfile
  import unittest
  from transformers import SPIECE_UNDERLINE, BatchEncoding, PLBartTokenizer, is_torch_available
  from transformers.testing_utils import get_tests_dir, nested_simplify, require_sentencepiece, require_tokenizers, require_torch
  from ...test_tokenization_common import TokenizerTesterMixin
label_desc: Use image node_id 10 for calling the PLBartPythonEnIntegrationTest obj's underlying member method code with example usage: obj.test_seq2seq_max_length() without return types