public static function validateCode($codeString) {
		$code = "<?php \$a = function(ContainerInterface \$container) { ".$codeString."\n}\n?>";
	
		$parser = (new ParserFactory())->create(ParserFactory::PREFER_PHP7);
	
		$stmts = $parser->parse($code);

		// If we are here, the code is correct.
		// Let's add a last check: whether there is a "return" keyword or not.
		if (stripos($code, "return") === false) {
			throw new Error("Missing 'return' keyword.", count(explode("\n", $codeString)));
		}
	}