code: def test_prepare_batch_empty_target_text(self):
      src_text = [
          "A long paragraph for summarization.",
          "Another paragraph for summarization.",
      ]
      for tokenizer in [
          self.default_tokenizer,
          self.default_tokenizer_fast,
      ]:
          batch = tokenizer(src_text, padding=True, return_tensors="pt")
          self.assertIn("input_ids", batch)
          self.assertIn("attention_mask", batch)
          self.assertNotIn("labels", batch)
          self.assertNotIn("decoder_attention_mask", batch)
  
imports: import json
  import os
  import unittest
  from transformers import BatchEncoding, LEDTokenizer, LEDTokenizerFast
  from transformers.models.led.tokenization_led import VOCAB_FILES_NAMES
  from transformers.testing_utils import require_tokenizers, require_torch
  from transformers.utils import cached_property
  from ...test_tokenization_common import TokenizerTesterMixin
label_desc: Use image node_id 8 for calling the TestTokenizationLED obj's underlying member method code with example usage: obj.test_prepare_batch_empty_target_text() without return types