private function parseExitExpression()
{
$this->tokenStack->push();
$token = $this->consumeToken(Tokens::T_EXIT);
$expr = $this->builder->buildAstExitExpression($token->image);
$this->consumeComments();
if ($this->tokenizer->peek() === Tokens::T_PARENTHESIS_OPEN) {
$expr->addChild($this->parseParenthesisExpression());
}
return $this->setNodePositionsAndReturn($expr);
}