code: def __call__(self, num_update, backbone: paddle.nn.Layer):
      if (
          self.rank == 0
          and num_update > 0
          and num_update % self.frequent == 0
      ):
          backbone.eval()
          with paddle.no_grad():
              self.ver_test(backbone, num_update)
          backbone.train()
  
file_path: insightface/recognition/arcface_paddle/dynamic/utils/verification.py
imports: import time
  import os
  import numpy
  import sklearn
  import paddle
  import logging
  from typing import List
  from utils.verification import evaluate
  from datasets import load_bin
label_desc: Use image node_id 4 for calling the CallBackVerification obj's underlying member method code with example usage: obj.__call__(num_update, backbone) without return types