///

/// tip

Notice that in this case we are using a standard Python `open()` function that interacts with a file.

So, it involves I/O (input/output), that requires "waiting" for things to be written to disk.

But `open()` doesn't use `async` and `await`.

Notice that the error also clearly states exactly the point where the validation didn't pass.

This is incredibly helpful while developing and debugging code that interacts with your API.

///

## Documentation { #documentation }

					// Additionally also check if domain is updated/missing with more
					// entries, if that is the case we should update the
					// new domain entries as well.
					continue
				}

				// if domain IPs intersect then it won't be an empty set.
				// such an intersection means that bucket exists on etcd.
				// but if we do see a difference with local domain IPs with
				// hostSlice from etcd then we should update with newer

    Note over Server: Server interprets headers<br/>(if --forwarded-allow-ips is set)

    Server->>Proxy: HTTP Response<br/>with correct HTTPS URLs

    Proxy->>Client: HTTPS Response
```

The **proxy** intercepts the original client request and adds the special *forwarded* headers (`X-Forwarded-*`) before passing the request to the **application server**.