public static function label($tokenId, array $tokens) {
		$token = $tokens[$tokenId];
		$hasName = in_array($token['id'], array(
			T_FUNCTION,
			T_CLASS,
			T_INTERFACE,
			T_VARIABLE,
		));
		if ($hasName) {
			if ($token['id'] === T_VARIABLE) {
				return substr($token['content'], 1);
			}
			$total = count($tokens);
			for ($key = $tokenId; $key <= $total; $key++) {
				if ($tokens[$key]['id'] === T_STRING) {
					return $tokens[$key]['content'];
				} elseif (in_array($tokens[$key]['content'], array('(', '{', ':'))) {
					break;
				}
			}
		}
		return null;
	}