final Path outsideDir = Files.createTempDirectory("outside");
        try {
            final Path hostDir = tempDir.resolve("evil.com");
            Files.createSymbolicLink(hostDir, outsideDir);

            final Map<String, Object> source = new LinkedHashMap<>();
            source.put("url", "http://evil.com/secret.html");
            source.put("content", "should not be written outside");