code: def get_random_line(self):
          
          # Similar to original tf repo: This outer loop should rarely go for more than one iteration for large
          # corpora. However, just to be careful, we try to make sure that
          # the random document is not the same as the document we're processing.
          for _ in range(10):
              if self.on_memory:
                  rand_doc_idx = random.randint(0, len(self.all_docs)-1)
                  rand_doc = self.all_docs[rand_doc_idx]
                  line = rand_doc[random.randrange(len(rand_doc))]
              else:
                  rand_index = random.randint(1, self.corpus_lines if self.corpus_lines < 1000 else 1000)
                  #pick random line
                  for _ in range(rand_index):
                      line = self.get_next_line()
              #check if our picked random line is really from another doc like we want it to be
              if self.current_random_doc != self.current_doc:
                  break
          return line
docs: Get random line from another document for nextSentence task.
          :return: str, content of one line