class_docstr: Transforms an input by replacing its tokens with words of mask language
  predicted.
  To accelerate transformation for long text, input single sentence to
  language model rather than whole text.
code: def __repr__(self):
      return "CNNASAL"
  
file_path: textflint/textflint/generation/transformation/UTCN/cn_nasal.py
imports: from ...transformation import CnWordSubstitute
  from pypinyin import lazy_pinyin
  from Pinyin2Hanzi import DefaultHmmParams
  from Pinyin2Hanzi import viterbi
label_desc: Use image node_id 2 for calling the CnNasal obj's underlying member method code with example usage: obj.__repr__() and returns: str