When bert distillation runs on saving model after training, an error occurs

[Qingsong Lv]

    save_checkpoint(args.iteration, model, optimizer, lr_scheduler, args)                                
  File "/home/lvqingsong/new/SwissArmyTransformer/SwissArmyTransformer/training/model_io.py", line 82, in
 save_checkpoint                                                                                         
    model_specific_args = extract_model_specific_args_from_model(args, module)                           
  File "/home/lvqingsong/new/SwissArmyTransformer/SwissArmyTransformer/training/model_io.py", line 44, in
 extract_model_specific_args_from_model
    md.add_model_specific_args(parser)
  File "/home/lvqingsong/new/SwissArmyTransformer/examples/bert/bert_ft_model.py", line 18, in add_model_
specific_args
    return super().add_model_specific_args(parser)
  File "/home/lvqingsong/new/SwissArmyTransformer/SwissArmyTransformer/model/official/bert_model.py", lin
e 48, in add_model_specific_args
    group.add_argument('--num-types', type=int)
  File "/usr/lib/python3.8/argparse.py", line 1398, in add_argument
    return self._add_action(action)
  File "/usr/lib/python3.8/argparse.py", line 1602, in _add_action
    action = super(_ArgumentGroup, self)._add_action(action)
  File "/usr/lib/python3.8/argparse.py", line 1412, in _add_action
    self._check_conflict(action)
  File "/usr/lib/python3.8/argparse.py", line 1551, in _check_conflict
    conflict_handler(action, confl_optionals)
  File "/usr/lib/python3.8/argparse.py", line 1560, in _handle_conflict_error
    raise ArgumentError(action, message % conflict_string)
argparse.ArgumentError: argument --num-types: conflicting option string: --num-types

[Qingsong Lv]

It seems that --num_types argument both in teacher and student model, which causes a conflict when extracting args. Is there anyway to fix this? @Sleepychord @dm-thu

[Sleepy_chord]

Maybe we can check if there is a duplication when enumerating the sub-models when saving? How do you think?

[Qingsong Lv]

Here is the branch that I fix DistillModel save and load problem: #61

[Sleepy_chord]

merged!