code: def test_case_insensitive(self):
      tokenizer = self.tokenizer_class.from_pretrained(
          "facebook/wav2vec2-lv-60-espeak-cv-ft"
      )
      input_text_up = "Hello how Are you"
      input_text_low = "hello how are you"
  
      input_ids_up = tokenizer(input_text_up).input_ids
      input_ids_low = tokenizer(input_text_low).input_ids
  
      self.assertEqual(input_ids_up, input_ids_low)
  
imports: import json
  import os
  import unittest
  from typing import Tuple
  from transformers import Wav2Vec2PhonemeCTCTokenizer
  from transformers.models.wav2vec2.tokenization_wav2vec2 import VOCAB_FILES_NAMES
  from transformers.models.wav2vec2_phoneme.tokenization_wav2vec2_phoneme import Wav2Vec2PhonemeCTCTokenizerOutput
  from transformers.testing_utils import require_phonemizer
  from ...test_tokenization_common import TokenizerTesterMixin
label_desc: Use image node_id 15 for calling the Wav2Vec2PhonemeCTCTokenizerTest obj's underlying member method code with example usage: obj.test_case_insensitive() without return types