code: def linear_dataset(a=2, size=1000):
      x = np.random.rand(size)
      y = x / 2
  
      x = x.reshape((-1, 1))
      y = y.reshape((-1, 1))
  
      return x, y
  
imports: import shutil
  from unittest import TestCase
  import numpy
  import pytest
  import tensorflow
  from zoo import init_nncontext
  from zoo.orca.data import XShards
  import zoo.orca.data.pandas
  from zoo.orca.learn.tf2 import Estimator
  from zoo.ray import RayContext
  import ray
  import os
label_desc: Use image node_id 1 for calling a global function with example usage: linear_dataset(a, size) and returns: x,  y