import org.checkerframework.checker.initialization.qual.UnknownInitialization;
import org.checkerframework.checker.nullness.qual.NonNull;

public class Suppression {

    @NonNull Suppression t;

    @SuppressWarnings("initialization.fields.uninitialized")
    public Suppression(Suppression arg) {}

    @SuppressWarnings({"fbc", "nullness"})
    void foo(@UnknownInitialization Suppression arg) {
        t = arg; // "fbc" error
        t = null; // "nullness" error
    }

    void test() {
        @SuppressWarnings("nullness:assignment.type.incompatible")
        @NonNull String s = null;
    }
}