code: private Vector<TreeNode> getFilteredChildren()
      {
          if (filteredChildren == null)
          {
              @SuppressWarnings("unchecked")
              Enumeration<? extends TreeNode> enumeration = 
                  delegateNode.children();
              Stream<TreeNode> stream = enumerationAsStream(enumeration);
              filteredChildren = 
                  filteredTreeModel.getFiltered(stream)
                      .collect(Collectors.toCollection(Vector::new));
          }
          return filteredChildren;
      }
docs: Returns the children of this node. These are the {@link FilteredTreeNode}
  instances that correspond to the children of the delegate node.
  
  @return The filtered children