### Performance Optimizations
- **Caching** - Bean descriptors and reflection metadata are cached for improved performance
- **Lazy initialization** - Resources and expensive operations are initialized only when needed  
- **Memory efficient** - Specialized collections like `LruHashMap` and `ArrayMap` for memory-conscious applications

Let's start with an example and then see it in detail.

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003.py hl[16,19] *}

Before Let's Encrypt, these **HTTPS certificates** were sold by trusted third parties.

The process to acquire one of these certificates used to be cumbersome, require quite some paperwork and the certificates were quite expensive.

But then **<a href="https://letsencrypt.org/" class="external-link" target="_blank">Let's Encrypt</a>** was created.

    }

    /**
     * Test validation of excessive negotiate context count.
     */
    @Test
    public void testExcessiveNegotiateContextCount() {
        byte[] buffer = createBasicNegotiateResponseBuffer();
        // Set SMB 3.1.1 dialect
        SMBUtil.writeInt2(0x0311, buffer, 4);
        // Set excessive negotiate context count (should be limited to 100)
        SMBUtil.writeInt2(1000, buffer, 6);

## OAuth2 { #oauth2 }

OAuth2 is a specification that defines several ways to handle authentication and authorization.

It is quite an extensive specification and covers several complex use cases.

It includes ways to authenticate using a "third party".

That's what all the systems with "login with Facebook, Google, X (Twitter), GitHub" use underneath.

## OAuth2

OAuth2 é uma especificação que define várias formas para lidar com autenticação e autorização.

Ela é bastante extensiva na especificação e cobre casos de uso muito complexos.

Ela inclui uma forma para autenticação usando “third party”/aplicações de terceiros.

{* ../../docs_src/handling_errors/tutorial006.py hl[2:5,15,21] *}

        this.dialectRevision = SMBUtil.readInt2(buffer, bufferIndex);
        final int negotiateContextCount = SMBUtil.readInt2(buffer, bufferIndex + 2);

        // Validate negotiate context count - prevent excessive memory allocation
        if (negotiateContextCount < 0 || negotiateContextCount > 100) {
            throw new SMBProtocolDecodingException("Invalid negotiate context count: " + negotiateContextCount + " (must be 0-100)");

        assertEquals(threadCount * operationsPerThread, encrypted.size(), "Should have encrypted results for each message");

        // Verify a sample of encrypted messages can be decrypted (to avoid extensive decryption that might fail)
        int sampleSize = Math.min(5, encrypted.size());
        for (int i = 0; i < sampleSize; i++) {
            try {