docstr: Return doc as key and doc sentence array as value
docstr_tok: ["Return","doc","as","key","and","doc","sentence","array","as","value"]
code: def _get_doc_sents(self, dataset):
      """Return doc as key and doc sentence array as value"""
      doc_sents = defaultdict(list)
      for s in dataset:
          doc = s.headers["doc_url"]
          doc_sents[doc].append(s)
      return doc_sents
  
imports: import math
  from underthesea.dictionary import Dictionary
  from collections import Counter, defaultdict
  from underthesea.utils import logger
  from datetime import date, timedelta
  import pandas
label_desc: Use image node_id 3 for calling the UDAnalyzer obj's underlying member method code with example usage: obj._get_doc_sents(dataset) and returns: doc_sents