Class Adder

tests/test_virtual_functions.py:275–280

            self.value = value

    class Adder(m.Adder):
        def __call__(self, first, second, visitor):
            # lambda is a workaround, which adds extra frame to the
            # current CPython thread. Removing lambda reveals the bug
            # [https://github.com/pybind/pybind11/issues/3357]
            (lambda: visitor(Data(first.value + second.value)))()  # noqa: PLC3002

    class StoreResultVisitor:
        def __init__(self):