public class SharpStackItem
{
    private Sharp thisSharp;
    private SharpStackItem previousStackItem;
    private boolean first;
    
    public SharpStackItem(Sharp sharp, Sharp previous)
    {
        thisSharp = sharp;
        
        previousStackItem = previous.getStackItem();
        
        first = false;
    }

    public SharpStackItem(Sharp sharp)
    {
        thisSharp = sharp;
        
        first = true;
        previousStackItem = null;
    }

    public boolean isFirst()
    {
        if(first) return true;
        else return false;
    }

    public Sharp getSharp()
    {
        return thisSharp;   
    }

    public SharpStackItem getPrevious()
    {
        return previousStackItem;   
    }
}
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<b>Notice</b>:  (null)(): [ALERT] Mailbox is over quota in <b>Unknown</b> on line <b>0</b><br />