code: def setUp(self):
      self.initial_lr = 1e-3
      self.test_opt_levels = ("O0", "O1", "O2", "O3")
  
imports: import unittest
  import torch
  import torch.nn
  import torch.nn.functional
  import torch.optim
  from apex import amp
  from utils import common_init, FLOAT
label_desc: Use image node_id 1 for calling the TestCheckpointing obj's underlying member method code with example usage: obj.setUp() without return types