@UnstableApi
    public FutureTransformingRequestPreparation<ResponseEntity<Path>> asFile(Path path) {
        requireNonNull(path, "path");
        return asEntity(ResponseAs.path(path));
    }
Writes the content of the {@link HttpResponse} to the {@link Path}.
For example:
<pre>{@code
WebClient client = WebClient.of("https://api.example.com");
CompletableFuture<ResponseEntity<Path>> response =
    client.prepare()
          .get("/v1/items/1")
          .asFile(Paths.get("..."))
          .execute();
}</pre>
core/src/main/java/com/linecorp/armeria/client/WebClientRequestPreparation.java