How to statically check with mypy that a dictionary has keys for all options in a Union type?

I have a Union type PossibleOption composed of n dataclasses, and I want to create a dictionary where the keys are instances of these classes. I need to statically check with mypy that the dictionary includes a key for each option in the Union. Here’s my current code:

from dataclasses import dataclass
from typing import Union

@dataclass
class Option1:
    def __hash__(self):   #don t focus too much on this method, A dictionary need a hashable key. that s all
        return hash(type(self))

@dataclass
class Option2:
    def __hash__(self):
        return hash(type(self))

@dataclass
class Option3:
    def __hash__(self):
        return hash(type(self))

PossibleOption = Union[Option1, Option2, Option3]

# I want to create a dictionary like this:
a = {Option1(): "a",Option2(): "bb",Option3(): "cc"}

I know that I could ask the user to give a function taking PossibleOption as paratmer and returning the the value like that:

 def equivalent_to_dictionary(po: PossibleOption) -> str:
    match po:
        case Option1():
            return "aa"
        case Option2():
            return "bb"
        case Option3():
            return "cc"

and mypy can check is each option are covered
But I want to keep things simple for the user…

Is there a way to statically check with mypy that each option (Option1, Option2, Option3 in this particular case) is present as a key in the dictionary?