class_docstr: Summarizer that picks sentences randomly.
code: def __call__(self, document, sentences_count):
      sentences = document.sentences
      ratings = self._get_random_ratings(sentences)
  
      return self._get_best_sentences(
          sentences, sentences_count, ratings
      )
  
imports: from __future__ import absolute_import
  from __future__ import division, print_function, unicode_literals
  import random
  from ._summarizer import AbstractSummarizer
label_desc: Use image node_id 1 for calling the RandomSummarizer obj's underlying member method code with example usage: obj.__call__(document, sentences_count) and returns: self