code: def _normalize_numbers(cls, text):
      number_to_kor = {
          "0": "영",
          "1": "일",
          "2": "이",
          "3": "삼",
          "4": "사",
          "5": "오",
          "6": "육",
          "7": "칠",
          "8": "팔",
          "9": "구",
      }
      new_text = "".join(
          number_to_kor[char] if char in number_to_kor.keys() else char
          for char in text
      )
      return new_text
  
imports: import re
label_desc: Use image node_id 1 for calling the KoreanCleaner obj's underlying member method code with example usage: obj._normalize_numbers(cls, text) and returns: new_text