class BaseColumnFieldDiffImpl implements BaseColumnFieldDiff {

    public static boolean isEqualOrNull( Object s1,
                                         Object s2 ) {
        if ( s1 == null
                && s2 == null ) {
            return true;
        } else if ( s1 != null
                && s2 != null
                && s1.equals( s2 ) ) {
            return true;
        }
        return false;
    }

    public  BaseColumnFieldDiffImpl();
    public  BaseColumnFieldDiffImpl( String fieldName,
                                    Object oldValue,
                                    Object newValue );

}