import com.khartec.waltz.model.EntityReference;
import com.khartec.waltz.model.Severity;</BUG>
import org.immutables.value.Value;
import java.time.LocalDateTime;
<BUG>import java.time.ZoneId;
@Value.Immutable</BUG>
@JsonSerialize(as = ImmutableChangeLog.class)
@JsonDeserialize(as = ImmutableChangeLog.class)
public abstract class ChangeLog {
public abstract EntityReference parentReference();

import com.khartec.waltz.model.EntityReference;
import com.khartec.waltz.model.Operation;
import com.khartec.waltz.model.Severity;
import org.immutables.value.Value;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.util.Optional;
@Value.Immutable
@JsonSerialize(as = ImmutableChangeLog.class)
@JsonDeserialize(as = ImmutableChangeLog.class)
public abstract class ChangeLog {
public abstract EntityReference parentReference();
