import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;

/**
 * A semi-persistent mapping from keys to values. Values are automatically loaded by the cache, and
 * are stored in the cache until either evicted or manually invalidated. The common way to build
 * instances is using {@link CacheBuilder}.
 *

## Partial updates with `PATCH` { #partial-updates-with-patch }

You can also use the [HTTP `PATCH`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PATCH) operation to *partially* update data.

This means that you can send only the data that you want to update, leaving the rest intact.

/// note

`PATCH` is less commonly used and known than `PUT`.

And many teams use only `PUT`, even for partial updates.

The application would process the request and send a **plain (unencrypted) HTTP response** to the TLS Termination Proxy.

<img src="/img/deployment/https/https06.drawio.svg">

### HTTPS Response { #https-response }

The TLS Termination Proxy would then **encrypt the response** using the cryptography agreed before (that started with the certificate for `someapp.example.com`), and send it back to the browser.

        end
        handler -->> client: HTTP error response
    end

    operation ->> client: Return response to client
    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info | 信息

    /**
     * Apply inbound settings and send an acknowledgement to the peer that provided them.
     *
     * We need to apply the settings and ack them atomically. This is because some HTTP/2
     * implementations (nghttp2) forbid peers from taking advantage of settings before they have
     * acknowledged! In particular, we shouldn't send frames that assume a new `initialWindowSize`
     * until we send the frame that acknowledges this new size.

        }

        do {
            try {
                send(request, response, config.getNetbiosRetryTimeout());
            } catch (final InterruptedIOException ioe) {
                // second query thread to finish gets interrupted so this is expected
                if (log.isTraceEnabled()) {
                    log.trace("Failed to send nameservice request for " + name.name, ioe);
                }

var ErrDone = errors.New("done for now")

var ErrRemoteRestart = errors.New("remote restarted")


// Stateless connects to the remote handler and return all packets sent back.
// If the remote is restarted will return ErrRemoteRestart.
// If nil will be returned remote call sent EOF or ErrDone is returned by the callback.
// If ErrDone is returned on cb nil will be returned.

    val requestHeadersEndListener =
      object : EventListener() {
        override fun requestHeadersEnd(
          call: Call,
          request: Request,
        ) {
          // Wait for the server to send the duplex response before acting on the 301 response
          // and resetting the stream.
          duplexResponseSent.await()
        }
      }
    client =
      client
        .newBuilder()

        end
        handler -->> client: HTTP error response
    end

    operation ->> client: Return response to client
    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info

You will also get autocompletion for the payload to send:

<img src="/img/tutorial/generate-clients/image03.png">

/// tip

Notice the autocompletion for `name` and `price`, that was defined in the FastAPI application, in the `Item` model.

///

You will have inline errors for the data that you send:

<img src="/img/tutorial/generate-clients/image04.png">