TypeScript/tests/cases/conformance/types/thisType/unionThisTypeInFunctions.ts

interface Real {
    method(this: this, n: number): void;
    data: string;
}
interface Fake {
    method(this: this, n: number): void;
    data: number;
}
function test(r: Real | Fake) {
    r.method(12);
}