code: def val_dataloader(self):
      return self.create_dataloader(self.valid_set, is_train=False)
  
imports: import argparse
  import dgl.graphbolt
  import dgl.nn.pytorch
  import torch
  import torch.nn
  import torch.nn.functional
  from pytorch_lightning import LightningDataModule, LightningModule, Trainer
  from pytorch_lightning.callbacks import EarlyStopping, ModelCheckpoint
  from torchmetrics import Accuracy
label_desc: Use image node_id 4 for calling the DataModule obj's underlying member method code with example usage: obj.val_dataloader() and returns: self