I'm finding the same object twice in my HashSet, and since I'm building
that HashSet using

Set getSelectedContentItems()
{
   Set      ciSet   = new HashSet();
   Iterator chIt = children.iterator();
   while (chIt.hasNext())
   {
     TreeNode child = (TreeNode)chIt.next();
     ciSet.addAll(child.getSelectedContentItems());
   }
   ciSet.add(myContentItem);
   return ciSet;
}

I'm wondering if somehow addAll is adding things without enforcing the
Set's constraint against duplicate items.  I've already checked that the
class "MyContentItem" class has a "public boolean equals(Object other)"
method.