docstr: take final feature
docstr_tok: ["take","final","feature"]
code: def take_final_feature(self, feature, index, name):
      """take final feature"""
      term_ids = L.gather(feature, index, overwrite=False)
  
      ernie_config = self.config.ernie_config
      self.slot_seqlen = self.config.max_seqlen
      position_ids = self._build_position_ids(term_ids)
      sent_ids = self._build_sentence_ids(term_ids)
  
      ernie_model = ErnieModel(self.config.ernie_config, "")
      feature, _ = ernie_model(term_ids, sent_ids, position_ids)
  
      if self.config.final_fc:
          feature = linear(feature, self.config.hidden_size, name)
  
      if self.config.final_l2_norm:
          feature = L.l2_normalize(feature, axis=1)
      return feature
  
imports: import os
  import json
  import numpy
  import pgl
  import paddle.fluid
  import paddle.fluid.layers
  from ernie import ErnieModel
  from pgl.utils.logger import log
label_desc: Use image node_id 3 for calling the ERNIESageV3Encoder obj's underlying member method code with example usage: obj.take_final_feature(feature, index, name) and returns: feature