code: def mxnet_pipe(mxnet_op, path, index_path):
      files, labels = mxnet_op(path=path, index_path=index_path)
      return files, labels
  
imports: from nvidia.dali import Pipeline, pipeline_def
  import nvidia.dali.ops
  import nvidia.dali.fn
  import nvidia.dali.types
  import nvidia.dali.tfrecord
  import os.path
  import tempfile
  import numpy
  from test_utils import compare_pipelines, get_dali_extra_path
  from nose_utils import assert_raises
  from nose2.tools import cartesian_params
  from nose import SkipTest
label_desc: Use image node_id 7 for calling a global function with example usage: mxnet_pipe(mxnet_op, path, index_path) and returns: files,  labels