/**
* {@inheritdoc}
*/
public function append(NodeDefinitionInterface $node)
{
if (isset($this->children[$node->getName()])) {
throw new InvalidArgumentException(sprintf('Config named "%s" in "%s" already defined.', $node->getName(), $this->getName()));
}
$this->children[$node->getName()] = $node->setParent($this);
return $this;
}
