code: def on_epoch_end(self, epoch, logs=None):
      if epoch % 4 != 0:
          return
      import random
  
      samples = random.sample(x_data, self.sample_count)
      translates, _ = self.model.predict(samples)
      print()
      for index in range(len(samples)):
          print(f"X: {''.join(samples[index])}")
          print(f"Y: {''.join(translates[index])}")
          print("------------------------------")
  
file_path: Kashgari/examples/web_qa_reading_comprehence.py
imports: import os
  import json
  from kashgari.tokenizers.bert_tokenizer import BertTokenizer
  from kashgari.embeddings import BertEmbedding
  from examples.tools import get_bert_path
  from kashgari.tasks.seq2seq.model import Seq2Seq
  import tensorflow
label_desc: Use image node_id 2 for calling the CustomCallback obj's underlying member method code with example usage: obj.on_epoch_end(epoch, logs) without return types