code: def check_is_vietnamese(self):
      if not self.is_word:
          return False
      for syllable in self.syllables:
          vowel_count = 0
          for character in syllable:
              if character not in VIETNAMESE_CHARACTERS_LOWER:
                  return False
              if character in VIETNAMESE_VOWELS_LOWER:
                  vowel_count += 1
          if vowel_count > 3:
              return False
          if not split_vietnamese_syllable(syllable):
              return False
      return True
  
file_path: underthesea/examples/text_normalize/process_viwiktionary.py
imports: from os.path import join
  from underthesea.file_utils import DATASETS_FOLDER
  from underthesea.pipeline.word_tokenize.regex_tokenize import VIETNAMESE_CHARACTERS_LOWER, VIETNAMESE_VOWELS_LOWER
  import re
label_desc: Use image node_id 3 for calling the Word obj's underlying member method code with example usage: obj.check_is_vietnamese() and returns: True, False, False, False, False