code: def get_avrg_feature_vector(self, tokens_str):
      if tokens_str is not None:
          return self.apply_get_from_cache(tokens_str)
      return None
  
file_path: nlp-architect/nlp_architect/data/cdc_resources/embedding/embed_elmo.py
imports: import logging
  import pickle
  from typing import List
  import numpy
  from nlp_architect.common.cdc.mention_data import MentionDataLight
  from nlp_architect.utils.embedding import ELMoEmbedderTFHUB
label_desc: Use image node_id 4 for calling the ElmoEmbedding obj's underlying member method code with example usage: obj.get_avrg_feature_vector(tokens_str) and returns: None, self