/**
* Removes from the list the last element that was returned by next()
* @return void
* @throws IllegalStateException
*/
public function remove()
{
if ($this->canRemove) {
$this->list->removeAt($this->index);
$this->canRemove = false;
} else {
throw new IllegalStateException("Cannot remove element unless next has been called");
}
}
/**
* Replace the node at the specified index in the
* receiver with the node argument
* @param int $index
* @param TreeNodeInterface $node
*/
public function replaceAt($index, TreeNodeInterface $node)
{
$node->setParent($this);
$this->children->removeAt($index);
$this->children->addAt($index, $node);
}
