code: def test_placeholder(self):
      pass
  
imports: import os
  import pytest
  from unittest import TestCase
  from test.pytorch.utils._train_torch_lightning import create_data_loader, data_transform
  from test.pytorch.utils._train_torch_lightning import create_test_data_loader
  from bigdl.nano.pytorch.vision.models import vision
  from bigdl.nano.pytorch import Trainer
  from bigdl.nano.utils.pytorch import TORCH_VERSION_LESS_1_10, TORCH_VERSION_LESS_2_0
  import pytorch_lightning
  import torch
  from torch import nn
  import torch.nn.functional
label_desc: Use image node_id 1 for calling the CaseWithoutscheduler obj's underlying member method code with example usage: obj.test_placeholder() without return types