How to make a class extention detected by Intellisense?

[Rambaud Pierrick (12rambau)]

Note

It's a duplicate from SO but as it seems to be either a bug or a limitation. so I narrowed down my question to the best IDE, i.e vscode

Context

I'm building an extention package on top of a Google API called Google Earth Engine: geetools. In short I want to add to an existing package object extra functions that are repetitive or complicated for new users.

The choice of using extention is dictated from the client VS server interaction of this API and I cannot use simple class definition if I want to remain server sided. The complete explaination and inspiration is documented here: https://geetools.readthedocs.io/en/latest/setup/pattern.html

Issue

My extentions are perfectly working but they remain undetected by Intellisence so I see no documentation and prototype when hover in VSCode, I cannot "go to definition" or even see the parameters names which makes it very difficult to use.

reproduce example

This is a completely unecessary overload of an empty class but it shows exactly what I perform and where it fails:

from typing import Callable

class Toto(object):

    def __init__(self):
        self.a = 1

    def print(self):
        print(self.a)


def register_class_accessor(klass: type, name: str) -> Callable:
    """Create an accessor through the provided namespace to a given class.

    Parameters:
        klass: The class to set the accessor to.
        name: The name of the accessor namespace

    Returns:
        The accessor function to to the class.
    """

    def decorator(accessor: Callable) -> object:
        class ClassAccessor:
            def __init__(self, name: str, accessor: Callable):
                self.name, self.accessor = name, accessor

            def __get__(self, obj: object, *args) -> object:
                return self.accessor(obj)

        # check if the accessor already exists for this class
        if hasattr(klass, name):
            raise AttributeError(f"Accessor {name} already exists for {klass}")

        # register the accessor to the class
        setattr(klass, name, ClassAccessor(name, accessor))

        return accessor

    return decorator

@register_class_accessor(Toto, "tools")
class Accessor:
    """Toolbox for the ``Toto`` class."""

    def __init__(self, obj: ee.Array):
        """Initialize the Array class."""
        self._obj = obj

    def tool_print(self):
        """Print the array."""
        print(f"tool object: {self._obj.a}")

The calls work:

Toto().tools.tool_print()
>>>> tool object: 1

but lookup is not working:

What should I modify in my code to make the accessor content detected ?