docstr: Returns
  -------
  PriorFactory
docstr_tok: ["Returns","--","--","--","-","PriorFactory"]
code: def use_neutral_categories(self):
      """
      Returns
      -------
      PriorFactory
      """
      term_df = self.term_ranker.get_ranks()
      self.priors += term_df[
          [str(c) + " freq" for c in self._get_neutral_categories()]
      ].sum(axis=1)
      return self
  
imports: import pandas
  import numpy
  from scattertext.termranking import AbsoluteFrequencyRanker
  from scattertext.termsignificance.LogOddsRatioInformativeDirichletPiror import LogOddsRatioInformativeDirichletPrior
label_desc: Use image node_id 8 for calling the PriorFactory obj's underlying member method code with example usage: obj.use_neutral_categories() and returns: self