private void readObject(java.io.ObjectInputStream stream)
        throws java.io.IOException, ClassNotFoundException {
        
        stream.defaultReadObject();
        try {
            buildExpression(cronExpression);
        } catch (Exception ignore) {
        } // never happens
    }
NOT YET IMPLEMENTED: Returns the final time that the 
<code>CronExpression</code> will match.
server/core/src/main/java/com/ke/schedule/server/core/common/CronExpression.java