code: def model_fn(model_dir):
      """Load the gluon model. Called once when hosting service starts.
  
      :param: model_dir The directory where model files are stored.
      :return: a model (in this case a Gluon network)
      """
      net = gluon.SymbolBlock.imports(
          symbol_file=os.path.join(model_dir, "model-symbol.json"),
          input_names=["data"],
          param_file=os.path.join(model_dir, "model-0000.params"),
      )
      return net
  
file_path: sagemaker-python-sdk/tests/data/mxnet_mnist/code/inference.py
imports: from __future__ import print_function
  import json
  import logging
  import os
  import mxnet
  import numpy
  from mxnet import gluon
label_desc: Use image node_id 1 for calling a global function with example usage: model_fn(model_dir) and returns: net