code: def test_empty(self):
      self._reset_partition_file()
      with open(partition_output, "w") as partition_file:
          partition_file.write("")
      test_partitioner = ImageSetsPartitioner()
      with self.assertRaisesRegexp(ValueError, ""):
          test_partitioner.initialise(
              test_sections,
              new_partition=False,
              data_split_file=partition_output,
          )
  
file_path: NiftyNet/tests/image_sets_partitioner_test.py
imports: from __future__ import absolute_import, print_function
  import os
  import tensorflow
  from niftynet.io.image_sets_partitioner import COLUMN_UNIQ_ID
  from niftynet.io.image_sets_partitioner import ImageSetsPartitioner
  from niftynet.engine.signal import TRAIN, VALID, INFER
  from niftynet.utilities.util_common import ParserNamespace
  from tests.niftynet_testcase import NiftyNetTestCase
label_desc: Use image node_id 3 for calling the ImageSetsPartitionerIllPartition obj's underlying member method code with example usage: obj.test_empty() without return types