code: def get_scores(self, query):
      raise NotImplementedError()
  
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 5 for calling the BM25 obj's underlying member method code with example usage: obj.get_scores(query) without return types