// Test case for Issue #425:
// https://github.com/typetools/checker-framework/issues/425

// @skip-test until the issue is fixed

import java.util.HashSet;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

public class Issue425 {
    private @Nullable Set<Integer> field = null;

    class EvilSet<T> extends HashSet<T> {
        public boolean add(T e) {
            field = null;
            return super.add(e);
        }
    }

    public void fail() {
        if (field == null) {
            field = new EvilSet<>();
        }

        field.add(1);
        // This line throws an exception at run time.
        field.add(2);
    }

    public static void main(String[] args) throws Exception {
        Issue425 m = new Issue425();
        m.fail();
    }
}