code: def validation_data_creator(config, batch_size):
      val_dataset = LinearDataset(
          2, 5, size=config.get("val_size", 400)
      )
      validation_loader = torch.utils.data.DataLoader(
          val_dataset, batch_size=batch_size
      )
      return validation_loader
  
imports: from bigdl.orca.learn.pytorch import Estimator
  from unittest import TestCase
  import pytest
  import torch
  import torch.nn
  import os
  import numpy
  from tempfile import TemporaryDirectory
label_desc: Use image node_id 5 for calling a global function with example usage: validation_data_creator(config, batch_size) and returns: validation_loader