code: def get_metrics(config):
      return ["accuracy", mx.metric.TopKAccuracy(3)]
  
file_path: BigDL/python/orca/test/bigdl/orca/learn/ray/mxnet/test_mxnet_gluon_multiple_input.py
imports: from unittest import TestCase
  import numpy
  import pytest
  import mxnet
  from mxnet import gluon
  from mxnet.gluon import nn
  from bigdl.orca.learn.mxnet import Estimator, create_config
label_desc: Use image node_id 5 for calling a global function with example usage: get_metrics(config) and returns: list