code: def test_empty_input(self):
      print("expect error here:")
      with pytest.raises(Exception):
          summary.histogram("dummy", np.ndarray(0), "tensorflow")
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from tensorboardX import summary
  from .expect_reader import compare_proto, write_proto
  import numpy
  import pytest
  import unittest
  import torch
label_desc: Use image node_id 7 for calling the SummaryTest obj's underlying member method code with example usage: obj.test_empty_input() without return types