code: def get_top_n(self, query, documents, n=5):
      assert self.corpus_size == len(
          documents
      ), "The documents given don't match the index corpus!"
  
      scores = self.get_scores(query)
      top_n = np.argsort(scores)[::-1][:n]
      return [documents[i] for i in top_n]
  
imports: from nboost.plugins import Plugin
  from nboost.delegates import ResponseDelegate
  from nboost.database import DatabaseRow
  import numpy
  from multiprocessing import Pool, cpu_count
  import math
  from nltk.stem import PorterStemmer
  from nltk.tokenize import word_tokenize
  from nltk.corpus import stopwords
  import nltk
label_desc: Use image node_id 6 for calling the BM25 obj's underlying member method code with example usage: obj.get_top_n(query, documents, n) and returns: unknown