Can you think of a way we can unit test this? It would be great if we could stand up an express server to receive the link PP requests. We could have something along the lines of:

```javascript
TestsUtil.withWebServer(12345, function(server, done) {
  server.head('/', function(req, res) {
    res.send(500, 'Head request error');
  });

  server.get('/', function(req, res) {
    // return a dummy html doc
  });

  // Create a link content item with link: http://localhost:12345

  // Let the preview process, and verify the item has successfully processed previews with embeddable = false
});
```

I bet that web server would be useful in other scenarios as well. Or maybe there is a library out there that provides the ability to easily mock a web server for these kinds of tests.