fillReq:   make(chan struct{}),
		fillReady: make(chan int64),
	}

	go func() {
		var rpos int64 // total bytes read into buffer

		defer func() {
			atomic.StoreInt64(&sr.end, rpos)
			close(sr.fillReady)
		}()

		for range sr.fillReq {
		scan:
			n, err := r.Read(sr.nbuf[:])

			if n == 0 {
				switch err {
				case io.EOF: // reader is exhausted
					return

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

## Read the Tutorial first { #read-the-tutorial-first }

The next sections assume you already read the main [Tutorial - User Guide: Security](../../tutorial/security/index.md){.internal-link target=_blank}.

func jsonToValue(result any) (*Value, error) {
	switch rval := result.(type) {
	case string:
		return FromString(rval), nil
	case float64:
		return FromFloat(rval), nil
	case int64:
		return FromInt(rval), nil
	case uint64:
		if rval <= math.MaxInt64 {
			return FromInt(int64(rval)), nil
		}
		return FromFloat(float64(rval)), nil
	case bool:
		return FromBool(rval), nil
	case jstream.KVS:

	closed   bool
}

func (pr *progressReader) Read(p []byte) (n int, err error) {
	// This ensures that Close will block until Read has completed.
	// This allows another goroutine to close the reader.
	pr.closedMu.Lock()
	defer pr.closedMu.Unlock()
	if pr.closed {
		return 0, errors.New("progressReader: read after Close")
	}
	return pr.processedReader.Read(p)
}

func (pr *progressReader) Close() error {

    @Override
    public PersistedToolchains read(File input, Map<String, ?> options) throws IOException {
        Objects.requireNonNull(input, "input cannot be null");

        try (InputStream in = Files.newInputStream(input.toPath())) {
            InputSource source = InputSource.of(input.toString());
            return new PersistedToolchains(new MavenToolchainsStaxReader().read(in, isStrict(options), source));

And it's possible that for your use case, the solution is in one of them.

///

## Read the Tutorial first { #read-the-tutorial-first }

You could still use most of the features in **FastAPI** with the knowledge from the main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank}.

                ClassRealm realm = entry.getClassRealm();
                for (String exportedPackage : exportedPackages) {
                    extRealm.importFrom(realm, exportedPackage);
                }
                if (exportedPackages.isEmpty()) {
                    // sisu uses realm imports to establish component visibility
                    extRealm.importFrom(realm, realm.getId());
                }
            }

            model.setProperties(externalProps);

            // Read again - should return fresh value (no caching in current implementation)
            assertEquals("externally.modified", wrapperProps.getProperty("initial.key"));

            // Now perform a write operation
            wrapperProps.setProperty("new.key", "new.value");

            // Read the initial key again - should return the current value

                            "content": {"application/json": {"schema": {}}},
                        }
                    },
                    "tags": ["items"],
                    "summary": "Read Items",
                    "operationId": "read_items_items__get",
                }
            },
            "/users/": {
                "get": {
                    "responses": {
                        "200": {

    stream = io.BytesIO(b"data")
    file = UploadFile(filename="file", file=stream, size=4)
    assert await file.read() == b"data"
    assert file.size == 4
    await file.write(b" and more data!")
    assert await file.read() == b""
    assert file.size == 19
    await file.seek(0)
    assert await file.read() == b"data and more data!"