private int getHashCode () {
        int result = propertyName != null ? propertyName.hashCode () : 0;
        result = 31 * result + (className != null ? className.hashCode () : 0);
        result = 31 * result + (clazz != null ? clazz.hashCode () : 0);
        result = 31 * result + (readMethod != null ? readMethod.hashCode () : 0);
        result = 31 * result + (writeMethod != null ? writeMethod.hashCode () : 0);
        result = 31 * result + hashCode;
        return result;
    }