Description:
------------
---
From manual page: http://www.php.net/countable.count
---

If I implement Countable interface in class RecursiveIteratorIterator show only nodes with count(node) > 0. If I remove Countable interface show all nodes.

Test script:
---------------
<?php
class TreeModel implements RecursiveIterator, Countable
{
	public $id;
	public $parentId;
	public $name;

	private $children = array();
	private $position = 0;
	private $counter = 0;

	public function addChildren(TreeModel $child)
	{
		$this->children[] = $child;
		$this->counter++;
	}
	
	public final function getChildren()
	{
		return $this->valid() ? $this->children[$this->position] : null;
	}

	public function hasChildren()
	{
		if (!$this->valid()) {
			return false;
		}
		
		return count($this->children[$this->position]->getChildren()) > 0;
	}

	public function current()
	{
		return $this->children[$this->position];
	}

	public function next()
	{
		$this->position++;
	}

	public function key()
	{
		return $this->position;
	}

	public function valid()
	{
		return isset($this->children[$this->position]);
	}

	public function rewind()
	{
		$this->position = 0;
	}

	public function count()
	{
		return iterator_count(new RecursiveIteratorIterator($this, RecursiveIteratorIterator::SELF_FIRST));
	}
}

$data = array(
	array('parentId' => 0, 'id' => 1, 'name' => 'Node 1'),
	array('parentId' => 0, 'id' => 2, 'name' => 'Node 2'),
	array('parentId' => 0, 'id' => 3, 'name' => 'Node 3'),
	array('parentId' => 1, 'id' => 4, 'name' => 'Node 1.1'),
	array('parentId' => 1, 'id' => 5, 'name' => 'Node 1.2'),
	array('parentId' => 1, 'id' => 6, 'name' => 'Node 1.3'),
	array('parentId' => 2, 'id' => 7, 'name' => 'Node 2.1'),
	array('parentId' => 3, 'id' => 10, 'name' => 'Node 3.1'),
	array('parentId' => 7, 'id' => 8, 'name' => 'Node 2.1.1'),
	array('parentId' => 8, 'id' => 9, 'name' => 'Node 2.1.1.1')
);

$root = new TreeModel();
$root->id = 0;
$root->parentId = null;
$root->name = 'ROOT';

$tempList = array($root);
foreach($data as $treeNode) {
	$treeItem = new TreeModel();
	$treeItem->id = $treeNode['id'];
	$treeItem->parentId = $treeNode['parentId'];
	$treeItem->name = $treeNode['name'];

	$tempList[$treeNode['id']] = $treeItem;
	$tempList[$treeNode['parentId']]->addChildren($treeItem);
}
unset($tempList);

$ritit = new RecursiveIteratorIterator($root, RecursiveIteratorIterator::SELF_FIRST, RecursiveIteratorIterator::CATCH_GET_CHILD);
foreach($ritit as $index => $treeItem) {
	echo $index, ': ', $treeItem->name, ": ", count($treeItem), "\n";
}
echo 'Total: ', count($root), "\n";

Expected result:
----------------
0: Node 1: 3
0: Node 1.1: 0
1: Node 1.2: 0
2: Node 1.3: 0
1: Node 2: 1
0: Node 2.1: 1
0: Node 2.1.1: 1
0: Node 2.1.1.1: 0
2: Node 3: 1
0: Node 3.1: 0
Total: 10

Actual result:
--------------
0: Node 1: 3
1: Node 2: 1
0: Node 2.1: 1
2: Node 3: 1
Total: 3