code: def _column_to_text(self, sentence):
      s = sentence
      tokens = s.split("\n")
      tokens = [t.split("\t") for t in tokens]
      tokens = [self.map_token(t) for t in tokens]
      s = "".join(tokens)
      s = s.strip()
      return s
  
file_path: underthesea/underthesea/corpus/ws_corpus.py
imports: import io
  from underthesea.corpus import Document, UnicodeTransformer, Corpus
  from os import listdir, mkdir
  from os.path import join
  from underthesea.util.file_io import write
label_desc: Use image node_id 3 for calling the WSCorpus obj's underlying member method code with example usage: obj._column_to_text(sentence) and returns: s