[Python] How to statically check with mypy that a dictionary has keys for all options in a...

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"}
# print(a[Option2()]) prints "bb" for example


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?

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