code: def get_model(config):
      class SimpleModel(gluon.Block):
          def __init__(self, **kwargs):
              super(SimpleModel, self).__init__(**kwargs)
              self.fc1 = nn.Dense(20)
              self.fc2 = nn.Dense(10)
  
          def forward(self, x):
              x = self.fc1(x)
              x = self.fc2(x)
              return x
  
      net = SimpleModel()
      net.initialize(mx.init.Xavier(magnitude=2.24), ctx=[mx.cpu()])
      return net
  
file_path: BigDL/python/orca/test/bigdl/orca/learn/ray/mxnet/test_mxnet_gluon.py
imports: from unittest import TestCase
  import numpy
  import pytest
  import mxnet
  from mxnet import gluon
  from mxnet.gluon import nn
  from bigdl.orca.ray import OrcaRayContext
  from bigdl.orca.learn.mxnet import Estimator, create_config
label_desc: Use image node_id 3 for calling a global function with example usage: get_model(config) and returns: net, x