@Override
    public int hashCode() {
        int result;
        result = (docId != null ? docId.hashCode() : 0);
        result = 31 * result + gid.hashCode();
        result = 31 * result + (int) (timestamp ^ (timestamp >>> 32));
        result = 31 * result + (removeEntry ? 1 : 0);
        return result;
    }
@author <a href="mailto:einarmr@yahoo-inc.com">Einar M R Rosenvinge</a>
documentapi/src/main/java/com/yahoo/documentapi/messagebus/protocol/DocumentState.java