code: def get_linear_data(a, b, size):
      x = np.arange(0, 10, 10 / size, dtype=np.float32)
      y = a * x + b
      return x, y
  
imports: from unittest import TestCase
  from bigdl.orca.automl.model.base_pytorch_model import PytorchModelBuilder
  from torch.utils.data import Dataset, DataLoader
  import pytest
  import numpy
  import torch
  import torch.nn
label_desc: Use image node_id 1 for calling a global function with example usage: get_linear_data(a, b, size) and returns: x,  y