private function doWhile() {
    $node = new DoWhileNode();
    $this->mustMatch(T_DO, $node, NULL, FALSE, TRUE);
    $node->addChild($this->statement(), 'body');
    $this->mustMatch(T_WHILE, $node, 'whileKeyword');
    $this->condition($node, 'condition');
    $this->endStatement($node);
    return $node;
  }