class_docstr: Source: https://github.com/adamfabish/Reduction
code: def rate_sentences(self, document):
      sentences_words = [
          (s, self._to_words_set(s)) for s in document.sentences
      ]
      ratings = defaultdict(float)
  
      for (sentence1, words1), (sentence2, words2) in combinations(
          sentences_words, 2
      ):
          rank = self._rate_sentences_edge(words1, words2)
          ratings[sentence1] += rank
          ratings[sentence2] += rank
  
      return ratings
  
file_path: sumy/sumy/summarizers/reduction.py
imports: from __future__ import absolute_import
  from __future__ import division, print_function, unicode_literals
  import math
  from itertools import combinations
  from collections import defaultdict
  from ._summarizer import AbstractSummarizer
label_desc: Use image node_id 4 for calling the ReductionSummarizer obj's underlying member method code with example usage: obj.rate_sentences(document) and returns: ratings