docstr: get train epoch num
docstr_tok: ["get","train","epoch","num"]
code: def epoch_num(self):
      "get train epoch num"
      return self.cfg.TRAIN.epoch
  
imports: import os
  import logging
  import paddle.fluid
label_desc: Use image node_id 11 for calling the ModelBase obj's underlying member method code with example usage: obj.epoch_num() and returns: self