code: def test_return_none(capture):
      from pybind11_tests import Parent
  
      with capture:
          p = Parent()
      assert capture == "Allocating parent."
      with capture:
          p.returnNullChildKeepAliveChild()
          pytest.gc_collect()
      assert capture == ""
      with capture:
          del p
          pytest.gc_collect()
      assert capture == "Releasing parent."
  
      with capture:
          p = Parent()
      assert capture == "Allocating parent."
      with capture:
          p.returnNullChildKeepAliveParent()
          pytest.gc_collect()
      assert capture == ""
      with capture:
          del p
          pytest.gc_collect()
      assert capture == "Releasing parent."
  
imports: import pytest
label_desc: Use image node_id 3 for calling a global function with example usage: test_return_none(capture) without return types