How to make IDE type-checking recognize dynamically added methods from a class decorator in Python?

Question

This is my code:

from typing import Type, TypeVar

T = TypeVar("T")


class NewMethodsMixin:
    def new_method(self) -> str:
        """This is a new method added by a mixin."""
        print("added by mixin")


def class_decorator(cls: Type[T]):
    class Decorated(NewMethodsMixin, cls):
        def __init__(self, *args, **kwargs):
            super().__init__(*args, **kwargs)
            cls.__init__(self, *args, **kwargs)

    return Decorated


@class_decorator
class MyClass:
    def old_method(self) -> str:
        print("original method")


my_instance = MyClass()
my_instance.old_method()  # 'original method'
my_instance.new_method()  # 'added by mixin'

This is how it looks in the IDE:

1

I wish to get type hints for old_method.

And if I use another approch:

...

def class_decorator(cls: Type[T]) -> Type[T]:
...

This is how it looks in the IDE:

2

Now I get the type hint for old_method, but lose the type hint for new_method.

If I use the Union:

...
def class_decorator(cls: Type[T]) -> Type[T] | Type[NewMethodsMixin]:
...

This is how it looks in the IDE:

3

Apparently, pylance or other type hints can handle the decorated class correctly, but if I inherit the new class, this will cause a failure.

For some reasons I prefer to use decorators instead of using class inheritance as my users may not be able to handle the issue of multiple inheritance. Is there any solution here?