import org.checkerframework.checker.initialization.qual.UnderInitialization;
import org.checkerframework.checker.initialization.qual.UnknownInitialization;

public class Subtyping {
    void test1(
            @UnknownInitialization(Object.class) Object unknownObject,
            @UnderInitialization(Object.class) Object underObject,
            @UnknownInitialization(Subtyping.class) Object unknownSubtyping,
            @UnderInitialization(Subtyping.class) Object underSubtyping) {
        // ::error: (assignment.type.incompatible)
        underObject = unknownObject;
        underObject = underSubtyping;
        // ::error: (assignment.type.incompatible)
        underObject = unknownSubtyping;
    }

    void test2(
            @UnknownInitialization(Object.class) Object unknownObject,
            @UnderInitialization(Object.class) Object underObject,
            @UnknownInitialization(Subtyping.class) Object unknownSubtyping,
            @UnderInitialization(Subtyping.class) Object underSubtyping) {
        unknownObject = underSubtyping;
        unknownObject = unknownSubtyping;
        unknownObject = underObject;
    }

    void test3(
            @UnknownInitialization(Object.class) Object unknownObject,
            @UnderInitialization(Object.class) Object underObject,
            @UnknownInitialization(Subtyping.class) Object unknownSubtyping,
            @UnderInitialization(Subtyping.class) Object underSubtyping) {
        // ::error: (assignment.type.incompatible)
        underSubtyping = unknownObject;
        // ::error: (assignment.type.incompatible)
        underSubtyping = unknownSubtyping;
        // ::error: (assignment.type.incompatible)
        underSubtyping = underObject;
    }

    void test4(
            @UnknownInitialization(Object.class) Object unknownObject,
            @UnderInitialization(Object.class) Object underObject,
            @UnknownInitialization(Subtyping.class) Object unknownSubtyping,
            @UnderInitialization(Subtyping.class) Object underSubtyping) {
        // ::error: (assignment.type.incompatible)
        unknownSubtyping = unknownObject;
        unknownSubtyping = underSubtyping;
        // ::error: (assignment.type.incompatible)
        unknownSubtyping = underObject;
    }
}