code: def simple_model(config):
      model = tf.keras.models.Sequential(
          [
              tf.keras.layers.Dense(10, input_shape=(1,)),
              tf.keras.layers.Dense(1),
          ]
      )
      return model
  
imports: import math
  import os
  import shutil
  import tempfile
  import pytest
  from unittest import TestCase
  import tensorflow
  import numpy
  from bigdl.orca.data.pandas import read_csv
  from bigdl.orca.data import SparkXShards, XShards
  from bigdl.orca.data.tf.data import Dataset
  from bigdl.orca.learn.tf2 import Estimator
  from bigdl.orca.ray import OrcaRayContext
  from bigdl.orca import OrcaContext
label_desc: Use image node_id 4 for calling a global function with example usage: simple_model(config) and returns: model