public function parse(\Twig_Token $token)
{
$stream = $this->parser->getStream();
$field = $stream->expect(\Twig_Token::NAME_TYPE)->getValue();
$stream->expect(\Twig_Token::BLOCK_END_TYPE);
if (FormState::$current === null) {
throw new \Twig_Error_Syntax(sprintf('Cannot render form field error [%s] outside a form element', $field), $token->getLine(), $this->parser->getFilename());
}
return new FormFieldErrorNode(FormState::$current, $field, $token->getLine(), $this->getTag());
}