code: def test_builtins_cast_return_none():
      """Casters produced with PYBIND11_TYPE_CASTER() should convert nullptr to None"""
      assert m.return_none_string() is None
      assert m.return_none_char() is None
      assert m.return_none_bool() is None
      assert m.return_none_int() is None
      assert m.return_none_float() is None
      assert m.return_none_pair() is None
  
imports: import sys
  import pytest
  import env
  from pybind11_tests import IncType, UserType
  from pybind11_tests import builtin_casters
label_desc: Use image node_id 11 for calling a global function with example usage: test_builtins_cast_return_none() without return types