(🎁) Narrow type based on method return type of union

[KotlinIsland]

I would expect the type of either to be narrowed to Maybe in the if block.

from typing import Literal

class Maybe:
    def should(self) -> bool:
        ...


class No:
    def should(self) -> Literal[False]:
        ...


no: No

if no.should():
    reveal_type(no)  # error: unreachable

either: Maybe | No

if either.should():
    reveal_type(either)   # Maybe | No