RosettaCodeData/Task/History-variables/AspectJ/history-variables-1.aspectj

public class HistoryVariable
{
    private Object value;

    public HistoryVariable(Object v)
    {
        value = v;
    }

    public void update(Object v)
    {
        value = v;
    }

    public Object undo()
    {
        return value;
    }

    @Override
    public String toString()
    {
        return value.toString();
    }

    public void dispose()
    {
    }
}