Not every module contributes to every runtime.

The core-runtime module defines each runtime:

- The target JVM for the runtime. Each runtime has its own JVM compatibility constraints.
- Some base services that are available to code hosted by the runtime. This varies by runtime.

# Response - Change Status Code { #response-change-status-code }

You probably read before that you can set a default [Response Status Code](../tutorial/response-status-code.md){.internal-link target=_blank}.

But in some cases you need to return a different status code than the default.

## Use case { #use-case }

For example, imagine that you want to return an HTTP status code of "OK" `200` by default.

    /**
     * The parser request this instance was created from.
     */
    @Nonnull
    ParserRequest parserRequest();

    /**
     * Flag representing parser processing result: if there were some fatal errors during
     * {@link Parser#parseInvocation(ParserRequest)} this method will return {@code true} and invoker should
     * handle this request as "early failure". In these cases, {@link #options()} usually is absent.

	// ARNPrefix prefix for "arn:aws:kms"
	ARNPrefix = "arn:aws:kms:"
)

// IsMultiPart returns true if the object metadata indicates
// that it was uploaded using some form of server-side-encryption
// and the S3 multipart API.
func IsMultiPart(metadata map[string]string) bool {
	if _, ok := metadata[MetaMultipart]; ok {
		return true
	}
	return false
}

All disks online
-----------------
- All Unformatted - format all and return success.
- Some Unformatted - format all and return success.
- Any JBOD inconsistent - return failure
- Some are corrupt (missing format.json) - return failure
- Any unrecognized disks - return failure

Some disks are offline and we have quorum.
-----------------
- Some unformatted - format all and return success,
  treat disks offline as corrupted.

   * -XX:+ExplicitGCInvokesConcurrent} is used.
   *
   * <p>Whenever possible, it is preferable to test directly for some observable change resulting
   * from GC, as with {@link #awaitClear}. Because there are no guarantees for the order of GC
   * finalization processing, there may still be some unfinished work for the GC to do after this
   * method returns.
   *

	writeSuccessResponseXML(w, encodeResponseList(response))
}

// ListObjectsV2MHandler - GET Bucket (List Objects) Version 2 with metadata.
// --------------------------
// This implementation of the GET operation returns some or all (up to 1000)
// of the objects in a bucket. You can use the request parameters as selection
// criteria to return a subset of the objects in a bucket.
//

# JSON Compatible Encoder { #json-compatible-encoder }

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }

./mvnw --projects '!guava-testlib,!guava-tests,!guava-bom,!guava-gwt' initialize -P print-java-11-home
export JAVA_HOME=$(<target/java_11_home)

# Gradle Wrapper overwrites some files when it runs.
# To avoid modifying the Git client, we copy everything we need to another directory.
# That provides general hygiene, including avoiding release errors:
#

        <form action="" onsubmit="sendMessage(event)">
            <label>Item ID: <input type="text" id="itemId" autocomplete="off" value="foo"/></label>
            <label>Token: <input type="text" id="token" autocomplete="off" value="some-key-token"/></label>
            <button onclick="connect(event)">Connect</button>
            <hr>
            <label>Message: <input type="text" id="messageText" autocomplete="off"/></label>
            <button>Send</button>