code: def test_chrono_duration_subtraction_equivalence():
      date1 = datetime.datetime.today()
      date2 = datetime.datetime.today()
  
      diff = date2 - date1
      cpp_diff = m.test_chrono4(date2, date1)
  
      assert cpp_diff == diff
  
file_path: coremltools/deps/pybind11/tests/test_chrono.py
imports: import datetime
  import pytest
  import env
  from pybind11_tests import chrono
label_desc: Use image node_id 6 for calling a global function with example usage: test_chrono_duration_subtraction_equivalence() without return types