import org.checkerframework.checker.nullness.qual.Nullable;
import org.checkerframework.checker.nullness.qual.RequiresNonNull;

public class SkipUses2 {

    static class SkipMe {
        static @Nullable Object f;

        @RequiresNonNull("f")
        static void foo() {}
    }

    static class DontSkip {
        static @Nullable Object f;

        @RequiresNonNull("f")
        static @Nullable Object foo() {
            return null;
        }
    }

    static class Main {
        void bar(boolean b) {
            SkipMe.f = null;
            SkipMe.foo();
            DontSkip.f = null;
            // :: error: (contracts.precondition.not.satisfied)
            DontSkip.foo();
        }
    }
}