code: def set_opt_method(self, opt_method):
      self.opt_method = opt_method
  
imports: import torch
  import torch.nn
  from torch.autograd import Variable
  import torch.optim
  import os
  import time
  import sys
  import datetime
  import ctypes
  import json
  import numpy
  import copy
  from tqdm import tqdm
label_desc: Use image node_id 10 for calling the Trainer obj's underlying member method code with example usage: obj.set_opt_method(opt_method) without return types