code: def test_id_to_char(self):
      try:
          self.empty_vocab.id_to_char(0)
          raise Exception("Should have raised KeyError")
      except:
          pass
      for k in self.phonemes.vocab:
          v = self.phonemes.char_to_id(k)
          self.assertEqual(
              self.base_vocab.id_to_char(v), self.phonemes.id_to_char(v)
          )
  
file_path: TTS/tests/text_tests/test_characters.py
imports: import unittest
  from TTS.tts.utils.text.characters import BaseCharacters, BaseVocabulary, Graphemes, IPAPhonemes
label_desc: Use image node_id 7 for calling the BaseVocabularyTest obj's underlying member method code with example usage: obj.test_id_to_char() without return types