code: def get_loss(config):
      from mxnet import gluon
  
      return gluon.loss.SoftmaxCrossEntropyLoss()
  
file_path: BigDL/python/orca/example/learn/mxnet/lenet_mnist.py
imports: import argparse
  from bigdl.orca import init_orca_context, stop_orca_context
  from bigdl.orca.learn.mxnet import Estimator, create_config
label_desc: Use image node_id 4 for calling a global function with example usage: get_loss(config) and returns: gluon